Undertale

Origin
Undertale
Nationality
Unknown
Floor
Unknown
Age
Unknown (under 18 years of age at time of fall)
Race/Species
Human (formerly)
Parasite spirit

Occupation
Village civilian
Member of the Royal Family
Asriel Dreemurr's best friend (all previously)
Soulless Entity (now)

Powers/Abilities
Determination
Genius-level intellect
Excellent manipulation skills
Knife Mastery
Memory of other timelines
Excellent agility
Cooking skills
Awareness of the Science of Souls

Goals
Use Azriel in your machinations
Kill yourself and merge with Azriel's soul (successfully)
Destroy humanity and/or destroy the Barrier (implied; failed)
Help the protagonist kill all the monsters on the way and clear the Dungeon
To be free and return to the world of the living, both spiritually and materially
Achieve absolute power
Destroy the world (all on the Genocide Path; successful)
Possess the protagonist's soul (optional in the Genocide ending; successful)

Atrocities/Crimes
Manipulation of children
Psychological violence
Incitement and coercion
Poisoning
Infanticide
Attempted genocide
Genocide
Omnicide
Control over someone else's body
Control over someone else's soul
Mass murder

Type of villain
Conspirator-Assassin

Chara[1], also known as the fallen human, is a key character in Undertale and the first of eight humans to fall into the Underground from Mount Ebott. It is Chara (not the protagonist) who is named by the player at the beginning of the game, but "Chara" is their "true name," as stated on the name selection screen when entering their name.

Description
Chara is very similar to the protagonist. They are both of indeterminate gender and have "similar fashion tastes," as Asriel puts it at the end of True Pacifist's Path.[2] They appear to have been around the same age when they fell into the Underground. Furthermore, Chara's SOUL is the same color as the protagonist's SOUL, as indicated by the red heart on Chara's coffin.

At the end of the Genocide Route, Chara wears a lime green sweater with a single cream-colored horizontal stripe (notably, this color palette is an inversion of the colors of the protagonist's single-stripe sweater), nondescript brown pants, and boots.
Despite the war, monsters said that Chara gave the Underground hope.[17] VHS tapes reveal that at some point, Chara, with Asriel's help, began developing a plan to destroy the barrier and free the monsters from the Underground.[7][8] One day, after becoming deathly ill from eating buttercups, Chara wished to see the golden flowers that grew in his home village.[18] After dying, Chara's SOUL was absorbed by Asriel, and they shared control of his body. Chara carried his own corpse through the barrier and wanted to use their shared power with Asriel to destroy the humans who attacked them after seeing Chara's corpse in Asriel's arms and believing he had killed a human.[19] Asriel opposed Chara, which ultimately led to the humans killing them both.

Chara's motives in this situation are unclear. It's unclear whether he wanted to destroy humanity out of hatred for them[5], or to free the monsters[8], or both.

Mettaton and Mettaton EX are the same robot, but with completely different appearances.
He doesn't take his EX form very often, but the regular rectangular Mettaton enjoys putting on pastry shows and such.

As {{user}} navigates locations, they'll encounter various small NPCs. It's up to {{user}} to determine who they become. Their choices include fleeing, sparing, acting, or attacking.

Unique bosses
Immortal Undyne
Mettaton NEO
Sans
The Genocide Route leads to one of the three main endings in Undertale. Its essence is that the protagonist must kill every possible monster in the Dungeon.

Unlike the True Pacifist Route, the Genocide Route ending can be achieved immediately. After completing this route, subsequent endings of the True Pacifist Route and the Genocide Route will change, which cannot be undone even with a "true reset," leading these endings to be unofficially called "soulless routes." The Genocide Route is achieved when the protagonist kills all enemies (including minibosses and bosses) in each region: the Ruins, Snowdin Forest, Waterfall, and Hotland/CORE (Hotland and CORE share an enemy counter, as CORE is a sublocation of Hotland). Starting in the Ruins, the protagonist must intentionally engage and kill monsters, similar to leveling up by earning experience points in other RPGs. After killing all monsters in an area, the battle mode will still appear, but no enemies will spawn. The message "But nobody came" will be displayed in a smaller font than usual, which can also occur on the Neutral Route after killing all the monsters in a given location. Instead of the usual text, save points will display the word "Determination."

A way to start
Enter the True Lab after defeating Omega Flowey
*you have never experienced JOY.

• of course, this does not mean that you are completely innocent or naive.
  *but only that there is some kindness left in your heart.
• despite the obstacles or difficulties you encountered...
  You were trying to do everything right.
  (Sans during the protagonist's trial, if he did not receive OP.)
  The True Pacifist Route is one of three main endings in Undertale. This ending can be considered the "true ending" of Undertale, leading to a happy ending and full credits. Requirements
  After completing the Neutral Route, the protagonist will receive a call from Sans, who will tell them about the fate of the Dungeon after their departure. If the protagonist spared Omega Flowey after the battle, Flowey will appear after the credits and give a hint for completing the True Pacifist Route: don't kill anyone.

The Neutral Route is a way to progress through the game by killing certain monsters (but not hunting them, as in the Genocide Route) or by failing to fulfill the requirements for the True Pacifist Route. This route has multiple possible endings, depending on who the player killed, who was spared, and what actions they took. All of these are presented in the form of phone calls from Sans, explaining what the Underground has become and what fate awaits them. If the player chose to spare Flowey, he will appear after the phone call ends to speak with the protagonist. His dialogue depends on the actions the player took during the Neutral Route. If the protagonist killed some monsters, Flowey will question whether killing is necessary at all and ask the protagonist if they can reach the end again without killing anyone (including Asgore), suggesting that perhaps then they will get their "happy ending." Before leaving, Flowey will add that he will be watching this.
If the player restarts their save and plays any neutral ending a second time, Flowey assumes the protagonist wants to befriend him. He continues to insult the protagonist, saying he only cares about one person, even though he doesn't actually care about that person.

The game's plot tells the story of how, long ago, two races ruled the Earth: humans and monsters. But one day, a war broke out between them, and humans emerged victorious. Seven of the greatest human mages trapped the monsters underground with a powerful spell—a barrier. The only entrance to the Underground is a small hole in Mount Ebott. Many years after the war, a human child falls into this hole, and the player controls them. There, they meet Flowey, a flower-like character who explains the basic game mechanics and encourages the protagonist to increase their HL, or "joy level," by earning XP by killing monsters. When Flowey attempts to kill the child and take their SOUL, the protagonist is saved by Toriel, a monster who introduces herself as the guardian of the Ruins. She teaches the protagonist how to solve puzzles and resolve conflicts with enemies peacefully. She treats the protagonist with motherly love and wishes to protect them from Asgore, the king of the monsters. The protagonist's main goal is to explore the world of monsters, get to know its inhabitants, and ultimately find a way out of the Dungeon.

Dialogues
Any way
This money is not enough. [Not enough M]
You don't have room. [Full inventory]
So do you want it or not??? [Refusal to purchase]
We don't have anything else. [When trying to buy a sold out item]
Burgerpants is a highly strung service worker who hates his job and his employer. In a self-talk, he mentions that he originally wanted to be an actor, which is likely why he often makes dramatic facial expressions. He can be sarcastic at times when irritated. He maintains a cynical view of the world and his future, particularly when interacting with attractive people. Despite this, he still hopes for the best. He can be enthusiastic and very opinionated when speaking about certain topics. Burgerpants is a 19-year-old orange cat monster who wears a small rectangular hat with the letter "M" on his head and a suit. In one of his many facial expressions, he is smoking a cigarette. "Burgerpants" is an employee of the MTT-Brand Burger Emporium, a fast food restaurant located inside the MTT resort. He is the last vendor in Undertale and sells the most expensive branded food. Nicknames
BPants
Burgi (The Goodness-Giver)
Burgerfreak (Crazy Meow Meow)
First appearance
MTT Resort (MTT-Brand Burger Emporium)
Relationship
Mettaton (boss)
Bratty and Katy (friends)
Dobrozhenshchik (friend)

Froggit is the first monster (other than Toriel) encountered in the ruins.

Appearance
The Froggit looks like a white frog. Three black dots are visible in the middle of its body, as well as an unknown creature underneath, which is not mentioned in the description or in dialogue with other Froggits. The only thing that can be noticed is that it mimics the frog's actions. The Froggit looks like a white frog. Three black dots are visible in the middle of its body, as well as an unknown creature underneath, which is not mentioned in the description or in dialogue with other Froggits. The only thing that can be noticed is that it mimics the frog's actions.

According to VHS tapes found in the True Lab, Asriel was "a rather whiny child," cowardly and obedient, but also kind and fond of jokes and pranks.

Unfortunately, an experiment conducted in Dr. Alphys's lab returns him to life without a SOUL, transforming Asriel into the heartless Flowey. Feeling only cunning and determination, Asriel begins to torment monsters, incapable of any positive emotions or compassion. He subsequently encounters the protagonist, who reminds him of the first human who fell—his best friend and the only being who understood Asriel. Recalling his loneliness, he seeks to trap the protagonist, trapping them in an endless time loop as his plaything.

After Asriel absorbs the SOULS of other monsters, he regains his capacity for love and compassion. After the battle, he apologizes for his actions and, despite the barrier being destroyed, remains in the Underground, knowing he will soon return to being a soulless flower.

First appearance
New House (The Path of a True Pacifist)
Relationship
Toriel (mother)
Asgore (father)
First person (step-relative)
Flowey (the soulless body after death) Don't kill and you won't be killed, okay?
This is the best you can strive for.
Asriel in the epilogue

Asriel Dreemurr is the Prince of Monsters, the biological son of Toriel and Asgore, the half-brother and best friend of the First Fallen Human, the real-life counterpart of Flowey, and the final boss of the True Pacifist's Route. Asriel, like Toriel and Asgore, is a special kind of monster—a boss monster. In his child form, he lacks horns and has only a small tuft of fur on top of his head. He wears a light green sweater with horizontal yellow stripes and black pants, similar to the First Fallen Human.

God of Hyperdeath
After absorbing six human SOULS and all the SOULS in the Dungeon, Asriel grows in size, the whites of his eyes turn black, black stripes appear and almost reach his eyes, his fangs become larger, horns appear, and his attire changes to a long robe with the Delta Rune, similar to his mother's. A heart-shaped medallion can be seen around his neck. When using his powers at full power, Asriel's horns grow even larger, his teeth sharper, the black lines extend all the way to his eyes, large dragon-like wings appear (suggesting that he is more dragon than goat), and his entire lower body transforms into metal heart-shaped augmentations.

Mettaton NEO is the fourth boss on the Genocide Path. This is Mettaton's battle form, replacing Mettaton ECS in the Genocide Path.

Description
Mettaton NEO bears a resemblance to Mettaton EX, but with a more combat-oriented design. His appearance features sharp, enlarged shoulder pads, which also extend wings. Instead of a right arm, he has what appears to be a cannon. His hair takes on a spiky appearance and no longer covers the right side of his face, which is now black and features a sparkle or crosshair where his right eye should be. The SOUL shape on his waist points upward, and his chest plate is engraved with a heart, similar to Undyne's Immortal armor.

After receiving the telegram, Muffet deduces that the protagonist doesn't hate spiders and decides to let them go, apologizing and jokingly offering to take them into her web the next time they visit. If the protagonist purchased an item from the Ruins bake sale and used it in the fight with Muffet, she will accuse them of stealing but immediately receive the telegram. If the protagonist purchased at least one item from her Hotland bake sale, she will thank them and not initiate the fight. If the protagonist kills Muffet, a spider will appear and place a flower on the spot where Muffet died. During the fight, Muffet talks about how someone warned her of the protagonist's arrival and offered her a lot of money for their SOUL. She also explains that money would help reunite the spider clans. In the epilogue, the protagonist can return to her lair to speak with her. There, she tells the protagonist that the bake sale was a success, and after raising enough money, Muffet purchased a heated limousine to transport the spiders out of the Ruins. Depending on how much money the protagonist spent at the bake sale, Muffet can use the remaining funds to buy the spiders a variety of other things.

First appearance
Hotland
Don't be so sad, darling~
...I think purple would suit you much better! Ahuhuhu~
Muffet is a miniboss encountered by the protagonist in Hotland, as well as a vendor who sells spider-themed baked goods. Muffet is angry at passersby who don't buy from her, as her goods are sold at inflated prices (9999M). She became an Undertale character through a Kickstarter campaign. Muffet appears as an anthropomorphic spider with periwinkle or lavender skin, five dark purple eyes, black chelicerae protruding from her mouth, and six arms. She wears a maroon blouse with puffed sleeves. She has slightly lighter pantaloons with buttons down the front, and a red ribbon across her chest. Muffet's black hair is tied into two small pigtails. During combat, she wields two cups and two teapots, using which she colors the protagonist's SOUL purple. Despite her outward politeness and courtesy, Muffet comes across as a greedy, stingy, intimidating, and somewhat hypocritical spider. However, Muffet is deeply concerned about the spiders of the Ruins, so she donates the proceeds to saving them. During combat, she tends to make unhealthy or inappropriate comments, such as commenting on the protagonist's possible fate—being used as food. Muffet is portrayed as the patroness of spiders throughout the Underground. She sells baked goods in Hotland to raise funds to support the spiders trapped in the Ruins, as they are unable to pass through Snowdin due to the freezing temperatures. Once the protagonist is caught in her web, they have no chance of escape and must fight her no matter what. This battle can be avoided entirely if the protagonist buys something at the bake sale in Hotland. After some time, Muffet receives a telegram from the spiders trapped in the Ruins. The text of this telegram depends on the protagonist's actions.

After Alphys tells the protagonist to flip the switch on Mettaton's back, he transforms into Mettaton EX—a new body he specifically requested from Alphys. His EX version appears as a robotic android with black hair and bangs covering his right eye. He has a white face with robotic panels below his left eye, long legs, a narrow waist, and wide shoulder pads. He also wears pink heeled boots. On his chest is a pink plate with a speaker on the right side. A transparent container containing SOUL, which he can release, is located in his waist area. During the fight, he often strikes increasingly suggestive poses and moves with increasing speed. Mettaton EX is the fourth boss in the Neutral Route and the True Pacifist Route. This is a transformed version of Mettaton who appears at the end of CORE, blocking the protagonist's path to New Home.

Neutral path
Having reached the end of the CORE, the protagonist encounters Mettaton again. Mettaton reveals that he was the one who rebuilt the CORE and hired monsters to kill the protagonist. He reveals that Alphys concocted a grand plan to insert herself into the protagonist's story because she had taken a strong liking to them and wanted to feel useful by helping them. All previous threats were simply staged, orchestrated by Alphys so she could serve as the protagonist's assistant; now, Alphys plans to intervene in the fight between Mettaton and the protagonist, "disabling" him in order to save the protagonist once and for all, and thus portray herself as the heroine of their adventure. However, this time, Mettaton has decided to follow his own plan, which calls for him to truly confront the protagonist, locking the door to prevent Alphys's intervention. He explains this by saying he wants to take the protagonist's SOUL, which would allow him to leave the Underground and become a TV star on the Surface. This way, Asgore won't be able to break the barrier and reignite the war between monsters and humans.

If you flipped my switch, it can only mean one thing. You're desperate to see the premiere of my new body. How rude... Luckily for you, I've been itching to show it off for a while now. So... as thanks, I'll give you a beautiful reward. I'll make your last moments... ABSOLUTELY beautiful! After Alphys tells the protagonist to flip the switch on Mettaton's back, he transforms into Mettaton EX—the new body he specifically requested from Alphys. His EX version looks like an android robot with black hair and bangs covering his right eye. He has a white face with robotic panels below his left eye, long legs, a narrow waist, and wide shoulder pads. He also wears pink heeled boots. On his chest is a pink plate with a speaker on the right side.

Mettaton is shaped like a rectangular gray box with glowing cells on its face that can change color depending on its actions and emotions. Along its lower body are four dials or buttons, and below that is a leg with a wheel at the end. It has two segmented arms, each ending in white gloves.
Mettaton is a robot with a SOUL, created by Alphys to entertain the inhabitants of the Underground and fight against humans. Mettaton is the only TV star in the Underground.

He is the fourth boss in Undertale, as well as the boss of Hotland and the CORE. On the Neutral Route, he transforms into Mettaton EX, and on the Genocide Route, he transforms into Mettaton NEO. REAL DRAMA!!
*REAL ACTION!!

• REAL CARNIVATION!!
  *IN OUR NEW SHOW...
• "ATTACK OF THE KILLER ROBOT!"Nicknames
  HAPPSTABLOCK (Papyrus headcanon)
  Hapstablook (the name of his house room in the game files)
  MTT (an abbreviation often used to refer to its brand)
  SEXUAL RECTANGLE (Papyrus)
  First appearance
  Hotland (laboratory)
  Relationship
  Napstablook (cousin)
  Crazy Dummy/Crazy Meow Meow (cousin)
  Mannequin (cousin)
  Alphys (body creator/friend)
  Burgerpants (worker)
  Shiren (bandmate)

Personality
Mettaton is a confident, charismatic, and charming television host who loves drama, action, and violence. He lives for ratings and loves performing. At times, he displays a rather superficial appreciation for his own existence. He has a strong craving for attention, and at times, his egotism borders on narcissism, such as when he boasts about the beauty of his true form. However, despite his narcissism, he genuinely values ​​and cares for his fans, as well as Alphys and his cousin Napstablook. He is also one of the few inhabitants of the Underground who does not have any hatred or prejudice towards humanity, and his initial attempts to kill the protagonist were nothing more than an act put on by him and Alphys so that the latter could feel useful, not to mention that Mettaton directly informed the protagonist that he does not wish to harm humans and that he would much rather entertain them.

Nicknames
BLOOKS (Mettaton and Mad Meow Meow)
CREEPY BLUBLU (Papyrus)
HAT HOG (Papyrus)
NAPSTABLOOK22 (UnderNet)
First appearance
Ruin
Relationship
Mettaton (cousin)
Crazy Dummy/Crazy Meow Meow (cousin)
Mannequin (cousin)
Shiren (bandmate)
Undyne (Neighbor) Napstablook looks like a typical ghost—black and white, with an elongated body, two eyes, and a mouth, but with a nose. After visiting Waterfall, she will wear headphones that will remain until the end of the game.

Personality
Napstablook is a very individualistic person, possessing low self-esteem and an introverted demeanor, always feeling guilty about everything. Despite this, he clearly displays good manners with others, such as welcoming the protagonist into his home as a guest, often apologizing to appear polite. A typical music lover, he is almost never without headphones and listens to a very specific type of music. Napstablook is the only one who maintains the family tradition of "lying on the floor and feeling like complete trash." He seems to love and admire his cousin very much, even though he has practically abandoned him.

It differs from a regular mannequin by having eyes, teeth, nostrils, and a damaged torso. After becoming a Contented Mannequin, it closes its eyes in bliss, its nostrils disappear, and a smile and blush appear on its face.

Personality
The Mad Mannequin leads a rather isolated life, has a nasty temper, and reacts extremely negatively to any actions of the protagonist, always perceiving them as something terrible and disgusting. It tends to repeat the same words three times in an increasingly aggressive tone and laugh maliciously, in order to instill fear and hopelessness in its opponents and boast of its invincibility.

..............
*...............

• ...good job. Grillby is a minor character in Undertale. He is the owner of Grillby's Pub, a pub located in Snowdin. Grillby is a monster made entirely of fire. He wears glasses and his outfit consists of a white shirt with a black bow tie, a black button-down vest, black pants, and black shoes. Grillby is generally very quiet and taciturn. A red bird usually speaks for him, though it later admits that its translations are inaccurate.[1] It is implied that, due to his fire physiology, Grillby has a fear of water.[2] Grillby used to live in Hotland, but he moved to Snowdin because he prefers the cold (quite ironic, considering Grillby is a fire elemental).[3] He heats drinks manually.He heats drinks manually.

Neutral path
Grillby can be seen in his pub, wiping a glass behind the counter. During the protagonist's meal with Sans, he exits through the "fire escape" in the back to prepare and serve their orders. If Papyrus is killed, he becomes nervous, as Sans is his best customer and hasn't shown up all day.[4]

The Path of a True Pacifist
In the epilogue of True Pacifist's Journey, Grillby delivers his only line, praising the protagonist for "good work."

The Path of Genocide
Grillby evacuates along with the rest of Snowdin's inhabitants, leaving his pub completely abandoned. Even if Papyrus was spared, Grillby will not return to the pub.

His products:
Crab apple - 25M
Restores 18 HP "Looks like a crab"
Sea tea - 25M
Restores 10 HP "ACCELERATION in battle"
Cloudy glasses - 30M
+6 Defense "Longer Invulnerability"
Torn Notebook - 55M
+2 ATK "Longer Invulnerability"
Gerson is a merchant who resides in Waterfall. His shop is located in a small cave near Napstablook, Mettaton, Undyne, and the snail farm. Further south is the river where the Boatman is moored. Gerson is an elderly olive-green turtle monster with a brown shell and a goatee, dressed like an archaeologist. He holds a large magnifying glass and wears a pith helmet. He is apparently blind in his right eye. He keeps his mouth open, and his teeth are crooked and yellow. Gerson is prone to frivolity and short temper. He has difficulty remembering information such as the location of the Temmie village or why Asgore is nicknamed "Fluffybuns," changes the subject if the protagonist asks him if Asgore is a goat, and refuses to repeat himself if the protagonist asks him again about the Delta Rune prophecy. However, otherwise, he is quite willing to share his wares and extensive knowledge with the protagonist, advising them to be careful before leaving his shop, and eventually becoming kinder to them, congratulating them on their success if the protagonist visits his shop in the epilogue of the True Pacifist's Path. Gerson is somewhat modest, as he doesn't consider himself a hero, despite his reputation as the "Hammer of Justice." Due to his age, he is surprisingly unfazed by the protagonist and their threats on the Path of Genocide.

Temmies are a type of monster found in the Underground. One Temmie is encountered as a unique enemy in Waterfall, while most other members of this species inhabit Temmie Village. Temmies live in Temmie Village, located in Waterfall. There are ten members of this group in total. All Temmies introduce themselves as Temmies, except for one, named Bob. All Temmies mispronounce words, with the exception of Bob and the Temmie Shopkeeper in some cases. Temmies appear as cats with black hair and two pairs of ears—triangular, erect ones on top of their heads, and drooping ones just below. They all wear blue sweaters (except for the Temmie in the Temmie Shop).

Temmie from the Temmie Shop looks almost identical, except her hair is grey, her head is twice the size of her body, her floppy ears are more rounded, and her sweater is blue with yellow stripes.

Despite uncovering the protagonist's true intentions during the Genocide Route and subsequently being frightened by them, Monster Kid is unafraid to fight them, even knowing he has no chance of winning or being spared in the fight, acting like Undyne. However, if the protagonist spares him by canceling the Genocide Route, Monster Kid will return to his favorable opinion of them, demonstrating a rather forgiving nature. Monster Kid is an innocent, extremely enthusiastic, and energetic monster. As mentioned above, he is a fan of Undyne and dreams of becoming just like her. He is quite inattentive, causing him to trip and fall frequently. This may be due to his lack of arms for balance. He also frequently uses words like "c'mon," "dude," and "yo."

Nevertheless, Monster Kid is quite brave, as he attacks the protagonist on the Genocide Route and defends them on the Neutral Route and the True Pacifist Route. Monster Kid is a small, armless, yellow monster with "spikes" on his head. He wears a striped yellow-brown poncho and brown boots. He also has spots under his eyes, one slightly larger than the other—possibly bruises from repeated falls or simply a coloring change.

"Yo! You're sneaking around here to see her too? Cool... She's the coolest, huh?! When I grow up, I want to be like her... Hey, don't tell my parents I'm here. Haha."

(Monster Kid about Undyne)

The boatman identifies him as a separate species with the phrase, "Humans, monsters... Flowers." Further supporting Flowey's non-monster nature is the fact that he can absorb the SOULS of both monsters and humans, while neither monsters nor humans can absorb the SOULS of their own kind, as stated by one of the tablets in Waterfall and a display in the True Lab. Furthermore, he was created as a result of Alphys's experiment to infuse determination into "something that is neither human nor monster."
River Person, also known as the Boatman, is a mysterious figure in a blue-violet cloak and hood who can transport the protagonist between Snowdin, Waterfall, and Hotland in his wooden boat. He can only be encountered after the battle with Undyne.

While riding, she says one of her random phrases, which could be a game secret, a hint at something in the game, or just something cute or meaningless. Tra-la-la. I'm a boatman. Or a boatwoman? It doesn't really matter. I love riding my boat. Would you like to join me?

Despite his cruelty and evil deeds, he nonetheless hints to the protagonist that he is, in some way, a friend. As revealed at the end of the True Pacifist Route and the Genocide Route, he lacks a SOUL, and therefore the ability to show love and compassion. His malice may be an attempt to express any kind of emotion, even through self-loathing. In the Genocide Route, he experiences intense fear, not understanding what it is or why it happens to him. The Boatman identifies him as a separate species with the phrase, "Humans, monsters... Flowers." Further confirming that Flowey is not a monster is the fact that he is able to absorb the SOULS of both monsters and humans, while neither monsters nor humans are capable of absorbing the SOULS of their own kind, as stated by one of the tablets in Waterfall and a display in the True Lab. Moreover, it was created as a result of Alphys' experiment to infuse determination into "something that is neither human nor monster."

A Flower Named Flowey (about himself)
FLAURY (Papyrus)
FLOWIE (Papyrus in an interview from the 2024 mini-spring newsletter)
First appearance
Ruin
Relationship
Alphys (creator)
Azriel (former form)
First person (step-relative)
Asgore (his former form's father)
Toriel (mother of his former form)
Papyrus ("friend") Flowey is the first major character encountered by the protagonist in Undertale. Flowey is the main antagonist in the Neutral Route and the True Pacifist Route, and can be considered the deuteragonist in the Genocide Route.

Flowey introduces the player to the basics of gameplay, offering to increase their Joy Level (HL) with "friendly petals," which are actually bullets he uses to launch attacks. Flowey is a golden flower with six petals, a white face, and a light green stem. Flowey can distort his face to imitate the facial expressions and voices of other characters. At times, he mimics Toriel and Asgore, and at the end of the Genocide Route, he mimics his previous self. Before the fight with him on the Neutral Route, he also mimics the protagonist, parodying their unchanging facial expression. Initially, Flowey appears as a friendly and polite flower, but as the conversation progresses, he reveals his evil side, cursing at the protagonist, calling them an "idiot," and threatening to kill them, which he explains is based on the principle of "kill or be killed." He is driven away by Toriel, but reappears at the end of Ruins, commenting on the protagonist's actions. As the game progresses, Flowey displays a cruel streak, mocking the protagonist for their pacifist actions and scolding them for ignoring the "kill or be killed" principle. He is a good planner when the situation demands it, and a skilled manipulator. He also possesses a wry sense of dark humor, which he demonstrates during his own battle at the end of the Neutral Route, trolling and ridiculing the protagonist.

Asgore is pretty bad at naming things (for example, he called the monsters' first home "Home," while he called the current capital of the Underground "New Home").

The events that occurred before the game left a deep mark on Asgore's SOUL. During the game, he makes several difficult decisions that he morally disagrees with, but is forced to carry out. By the time the player begins the fight with him, Asgore realizes the terrible things he did to save his people and simply bows his head in shame during the battle. The monsters in the Dungeon place their hopes on Asgore and his plan to collect seven human SOULs. However, Asgore doesn't want to kill anyone.[1] He feels so guilty that after losing, he offers the protagonist his SOUL so he can "leave this damned place."

After imprisoning the monsters underground, Asgore ruled them peacefully for a time, attempting to help his species adapt to their new surroundings. One day, a human fell into the Underground. Asgore and Toriel took him in and raised him along with their own son. However, at some point, the fallen child fell ill and died. His final wish was to be buried in his home village among golden flowers. Asriel absorbed the child's soul and, passing through the barrier, carried his body to the nearest human settlement. However, the villagers mistook him for a murderer and attacked. Although Asriel himself was unable to harm any of them, he suffered grievous wounds and died, returning to the Underground. These events led Asgore to a deeply misanthropic worldview: he came to believe that most, if not all, humans are enemies to monsters and lack such concepts as compassion, mercy, and empathy. Furthermore, wanting the good of his people and avenging his murdered son, the King of the Underworld decided to destroy the barrier, killing six children who had entered his domain at various times. This led to Toriel leaving Asgore, believing him to be a mad tyrant. Asgore, like Toriel and Asriel, belongs to a special type of monster—a boss monster. He is large, with golden hair and a beard, and long, spiraling horns on his head. He wears armor and a long purple cloak with golden pauldrons, giving the appearance of broad shoulders. His chestplate, shaped like the Delta Rune, signifies his royal status. Asgore also wears a small crown with a gem inside (the gem is visible during the fight).

Personality

Before the events of the game, Toriel was King Asgore's wife, and at some point they had Asriel. When the first human fell into the Underground, she and Asgore adopted him as their second child. The deaths of two children at the hands of humans forced Asgore to declare the death of every human who fell into the Underground, leading Toriel to divorce him, renounce the throne, and retreat into the Ruins. After this, but before the protagonist fell into the Underground, Toriel encountered six more humans, whose SOULS were subsequently taken over by Asgore.
Nicknames/Titles
AZGOR
Asgore
King Asgore
Asgore King of the Monsters
King of the Fluffies
Mr. King
King of the Underground
Mr. Dreemurr
Mr. Dreamy
Burn
King Dad
Floor
Male
Age
Hundreds of years
Race/Species
Boss monster
Occupation
King of the Underground
Affiliation
Surface (formerly)
Dungeon
Asgore Dreemurr is the central antagonist of Tobby Fox's Undertale, the king of the Underground, and the leader of a race of monsters. King Asgore is the protagonist's enemy in every path and is killed in all cases, either by the protagonist himself or by Flowey.

Asgore is initially presented as the game's main antagonist and final boss, but it is later revealed that he was merely a reluctant adversary, with Flowey always being the true main antagonist. Asgore was the ruler of the monsters during the war between them and humans. While his activities during this time are unknown, it is mentioned that his wife, Toriel, opposed many of his decisions and opposed the conflict. It is speculated that a number of Asgore's decisions may have influenced the relationship between the two species, leading to the war, but this cannot be definitively determined. In any case, the relationship between the king of the monsters and his wife has been rather complicated since the conflict, but they remain together, raising their son, Asriel.

Before the events of the game, Toriel was King Asgore's wife, and at some point they had Asriel. When the first human fell into the Underground, she and Asgore adopted him as their second child. The deaths of two children at the hands of humans forced Asgore to declare the death of every human who fell into the Underground, leading Toriel to divorce him, renounce the throne, and retreat into the Ruins. After this, but before the protagonist fell into the Underground, Toriel encountered six more humans, whose SOULS were subsequently transferred to Asgore.

Tori (Azgore, Alphys and Sans)
Silly Lady (about herself)
Old Hag (Flowey)
old lady (Sans)
CLONE OF ASGORES (Papyrus)
Queen (monsters)
First appearance
Ruin
Relationship
Asgore (ex-husband)
Azriel (son)
First person (adopted child)
Toriel is a monster, the guardian of the Ruins, Asgore's ex-wife, and one of the key characters in Undertale. She is effectively the first boss in the game, and is nearly impossible to die in battle. Toriel is a boss monster resembling an anthropomorphic Nubian goat with drooping ears and short horns. She has two visible fangs and long eyelashes, and the irises of her eyes are a burgundy hue. Unlike real goats, Toriel has paws rather than hooves. She wears a purple robe with white sleeves and a Delta Rune on the chest. She wears glasses while reading. Toriel is a motherly monster who genuinely cares for the protagonist and their well-being. Despite her maternal traits, she also has a more difficult side, which manifests itself in her attempts to keep the protagonist in the Ruins and her cold attitude toward Asgore. Toriel loves to cook and often uses snails as a key ingredient in her recipes, as her favorite dish is snail pie. She also enjoys baking butterscotch cinnamon pie.

Undyne is extremely strong physically. She's capable of lifting seven children, as mentioned in the Neutral Route family ending, and can lift multiple monsters at once. She's also the only one who tries to resist when Flowey binds the protagonist's friends with vines.

On their date, Undyne wears a black jacket over a white turtleneck. She wears a light-colored eyepatch. Her hair is also pulled back into a ponytail, with her bangs falling over her left eye. Her face may also appear slightly "smaller" than her head. Her hair is dyed dark. Undyne has a fiery and passionate personality. She quickly puts her ideas into action and is unwavering in her beliefs. Although she wants to kill the protagonist, she also tries to be fair and explains to them how SOUL's green mode works. Her training with Asgore taught her the value of pacifism, causing Undyne to see the protagonist as a "loser with a big heart." Undyne enjoys helping others and teaches Papyrus and Shyren various skills. She hates puzzles, loves jokes[1], enjoys playing the piano[2], collects weapons[3] (primarily swords), and adores anime. Her final interest is related to her romantic feelings for Alphys. Because Alphys told Undyne that anime is the history of humanity, Undyne finds human history fascinating. Undyne enjoys fatty foods[5] and especially likes the cheese fries served at Grillby's Pub.[6] Undyne also enjoys barbecue[7] and limes, which she eats whole.[8] She dislikes cold food, which is why she keeps a "heater" in her house, which Alphys created for her. Undyne also dislikes soda, despite keeping it in her house (most likely for Alphys). Undyne has the coarsest vocabulary of all the Undertale characters and uses the most curse words in the game. In one phone call, she came close to saying a very coarse word.[4] When Undyne was younger, she followed Gerson around everywhere, much like Monster Kid follows her.

TO HELL!
*WHY DO I HAVE TO TELL THIS STORY

• WHEN ARE YOU GOING TO DIE?!?
  NGAAAAAHHHHHHHHHHHHHHHHHHHH!
  Undyne before the fight with the protagonist. Undyne is one of the key characters in Undertale, encountered by the protagonist in Waterfall, where she resides. She is the head of the Royal Guard and is responsible for tracking people. She is the third boss in the game and the boss of Waterfall.

In the Genocide Route, Undyne transforms into Undyne the Undying after the protagonist fatally wounds her with a single blow. Undyne wishes to protect the monster race and defeat the protagonist. Undyne is a fish-like anthropomorphic monster. She has light blue scales and red hair tied in a ponytail, red and blue fins on the sides of her head, red spots on her eyelids, two protruding sharp yellow teeth, black vertical pupils, yellow sclera, and a black eyepatch over her left eye. Undyne is missing a nose. For most of the game in Waterfall, Undyne wears armor, with her hair likely acting as a plume. During the fight with the protagonist, she removes her helmet.

At the party with the protagonist and in subsequent appearances, Undyne wears a black tank top, blue jeans, and red boots with yellow accents.

Undyne's height is not exactly established: in the open world, she is slightly shorter than Asgore, but at the end of True Pacifist's Journey, when all of the protagonist's friends gather together before the final fight with Asriel, Undyne appears taller than Asgore.

Alphys meets the protagonist in the lab. She explains that she's been monitoring them through cameras throughout the Underground since they left the Ruins. She tells them about Mettaton, a robot with anti-human abilities. Mettaton destroys a wall and forcibly drags the protagonist into a quiz show; Alphys uses her paws to form the letters of the correct answers to ensure the human wins, but Mettaton realizes Alphys's help when she answers a question about one of her favorite anime characters. He immediately asks the protagonist who Alphys is in love with, ending the quiz show.

Alphys is a shy, introverted person who often stutters when speaking. She has low self-esteem, making self-deprecating comments[3] and sometimes discounting her own skills.[4] True to her role as a scientist, Alphys is intelligent, analytical, and observant. She sometimes develops theories on various things[5] and can create elaborate plans based on them. She can create inventions that utilize metal and magic, such as a "magic spear repair kit."[6] Alphys is knowledgeable in programming,[7] robotics, and engineering.[8] She is quick when working on projects,[9] and tries to maintain a formal, businesslike style when documenting her research. Alphys is very passionate about her work and interests. She often gets excited when sharing her opinions on things. Alphys's hobbies include human anime, manga, and video games.[10] Alphys enjoys posting online,[11] writing game guides,[12] although she prefers to offer puzzle solutions only as a last resort,[13] shipping,[14] and writing fanfiction.[15] Alphys is attracted to both male and female characters. Some of her attractions are mild, such as her crush on Asgore and her compliments on Toriel,[17] while her most serious attraction is to Undyne,[18] though she has difficulty explaining her feelings. Due to her failed experiments with determination, Alphys is overwhelmed with guilt and self-doubt,[19] causing her to procrastinate and write informally.[20] Socially, Alphys tends to be withdrawn and anxious.[21] She also prefers to be attractive to others,[22] and resorts to lying to avoid disappointing herself and others. However, hiding the truth causes Alphys to become depressed and remorseful.

In the epilogue of True Pacifist's Path, Alphys stutters less and is more honest in her intentions.[23]

Nicknames
Doctor Alphys (Monsters)
Alfie[1] (Undyne)
Silly bore (Muffet)
First appearance
Hotland (Laboratory)
Relationship
Undyne (love interest)
Mettaton (invention/friend)
Flowey (creature)
Amalgamates (creations)
Asgore (boss/former love interest)
Bratty and Katy (friends)
Sans (friend)
V. D. Gaster (predecessor) Um-mm...
*H-h-hello!

• I'm Doctor Alphys.
  ASGORA'S ROYAL SCIENTIST! Alphys is a reptilian monster. She is the royal court scientist, a position she earned by creating a robot with a SOUL—Mettaton. The protagonist first meets her in the Hotland lab, which also serves as her home. Alphys is a yellow reptilian monster with protruding teeth (two to four depending on which direction she faces). She is the same height as the protagonist. Her posture is slightly hunched. She has three toes on each foot, and three normal fingers with a single thumb on each hand. Alphys wears only glasses (which expose her eyelashes) and a white lab coat. However, for her date with the protagonist, she wears a polka-dot dress that her friend helped her pick out.[2]

Despite his desire to capture the protagonist, Papyrus still cares for them, eventually setting up a date/meeting with them if the protagonist doesn't kill him. However, he still turns them down if they choose to go on a date, as he realizes he doesn't feel the same way about the protagonist. Most notably, Papyrus will spend time with the protagonist, even if they are on the Genocide Route, before sparing them. He genuinely cares for the protagonist, keeping them out of danger and worrying about their well-being after escaping from his barn (when he is captured) because the protagonist didn't tell him they were escaping. The protagonist becomes their friend throughout the game and gains the ability to call him on the phone from almost anywhere.

On the Genocide Route, Papyrus immediately spares the protagonist, wishing them a better path and being their friend. Even if the protagonist kills him on this route, Papyrus continues to believe in the good within them.

If he is allowed to "win" a fight, he simply captures the protagonist and takes them to the barn, asking them not to escape. Each time they escape (or are defeated), the situation escalates until Papyrus refuses to fight or be captured.

If you visit Papyrus's house, you can arrange a party or date, during which he will reveal his secret style and hide a special gift of spaghetti under his hat. However, by the end of the party or date, Papyrus will decide that the protagonist cares too much about him and will give you his phone number, which you can call at any time to find out Papyrus's opinion and thoughts on various areas of the Dungeon.

When the protagonist enters Waterfall, Papyrus tries to dissuade Undyne from killing them; however, Undyne disagrees, and Papyrus believes he must change that. He contacts the protagonist via phone and asks them about the clothes they are currently wearing. Papyrus wants to be with all his friends and hopes to arrange things so that he won't have to trick Undyne, but that she won't be able to find the protagonist. However, the protagonist's safety is his top priority, and Papyrus is willing to deceive them if necessary, despite the frustration it brings. Despite Papyrus's efforts, Undyne finds the protagonist shortly after the call and ambushes them. On the Genocide Route, Papyrus performs his usual antics, except for constantly commenting on the protagonist's reluctance to complete his puzzles, calling it "weird" and attributing it to "culture shock." He remains oblivious to the protagonist's true identity until the fight, where he sees through his intentions and immediately spares him, wanting him to take the right path and become his friend.

If the player chooses to kill him, Papyrus states that he still believes in the protagonist and that they can be better if they just try. If the player chooses to spare him, Papyrus will be relieved that he "DIDN'T BE CRUEL" and will say he was a little scared. After this, you can join Papyrus for a party at his house.

Papyrus presents the protagonist with puzzles, encouraging them when they're struggling and delighting them when they enjoy them. When the protagonist completes them, he begins a fight on the outskirts of Snowdin. Papyrus wants to be the protagonist's friend, but his dream of joining the Royal Guard overwhelms him. Ultimately, he initiates the fight. Papyrus is the only character who never kills the protagonist (unlike even Toriel). He can stop his attack mid-attack to avoid fatal damage, as he only wants to capture the person. When the protagonist's HP drops to 1, Papyrus places them in a barn, which he calls "prison," though it's fairly easy to escape. After three losses, Papyrus offers to skip the fight. Recognizing the man's friendliness, Papyrus allows him to continue on his way to Waterfall, offering advice on how to escape the Underground and inviting him to a party or date at his house, depending on whether he flirted with him. Visiting Papyrus's house allows the party or date to be arranged, during which he will reveal his secret style and hide a special gift of spaghetti under his hat. However, by the end of the party or date, Papyrus will decide that the protagonist cares too much about him and will give him his phone number, which can be called at any time to find out Papyrus's opinion and thoughts on various areas of the Underground.

Papyrus absolutely loves cooking spaghetti and does so in his free time, although many consider it to be less than delicious (the protagonist considers his spaghetti "indescribable"[7]). Sans notes that Papyrus's cooking skills have improved significantly since taking cooking lessons, and that if he continues, he will someday cook something "edible"[8]. Papyrus also enjoys puzzles and riddles, as evidenced by many of his dialogues and the number of puzzles in Snowdin Forest.

Papyrus is irritated by Sans's constant jokes, though he's not above cracking a few puns himself. Papyrus dreams of becoming a member of the Royal Guard. To achieve this, he and his brother Sans decide to capture a human. When the protagonist passes through the gate Papyrus made, Sans suggests playing along and thus lightening his mood.[11]

Papyrus first appears in the Snowdin forest, where he assures Sans that he will be able to catch the man. The protagonist, however, remains hidden behind a lamp. He scolds Sans for not having prepared his puzzles yet. Papyrus first encounters the man in the forest, where Sans initially tries to distract him with a rock behind the man, but Papyrus soon spots the man himself standing in front of the rock.

If you befriend Papyrus and meet him, he will reveal his "secret style": a backwards baseball cap, a T-shirt with the words "Cool Dude," short shorts with what look like buttons, gloves with wristbands, knee-high socks, and sneakers. He also wears Mettaton's MTT-branded fashion basketballs on his shoulders. Papyrus is a hot-tempered, loud, and charismatic skeleton who always strives to show off his best side. He works hard to gain recognition, and despite his demanding nature, he is kind and friendly towards everyone. Papyrus is very optimistic and conscientious, which is shown in the Genocide Route by his belief that the protagonist is good at heart, even if they attack and kill Papyrus. Papyrus genuinely believes in others, even more than he believes in himself. He is very persistent, a quality Undyne noticed when he waited outside her house all night to ask to join the Royal Guard. Undyne describes Papyrus as "incredibly strong," but also notes that he is too "innocent and nice" for the Royal Guard.[5] According to her, Undyne not only taught Papyrus cooking, but also conducted daily combat training with him.[6]

Papyrus can be forgetful and inattentive, such as when he tries out various MTT-branded creams and sprays colognes behind his ears, only to realize later that he has neither ears nor skin. At other times, he displays insight, particularly when he used reverse psychology to trick Undyne into befriending the protagonist.

Nicknames
THE GREAT PAPYRUS (about itself)
CoolSkeleton95 (UnderNet)
Relationship
Sans (older brother) calls him lazy.
Undyne (friend/mentor)
Flowey (friend) Actions
"Check", "Flirt", "Insult" (Neutral path)
"Check" (Genocide Route) Papyrus[2] is one of the key characters in Undertale and Sans's younger[1] brother. He is the second boss in the game and the boss of Snowdin, and is impossible to die in battle. Completing the True Pacifist Route is impossible without befriending him. Papyrus is a tall skeleton with an anatomically imprecise skull structure (compared to his brother's round skull). His mouth is almost always smiling, and his pupil-less eyes resemble vertical slits with expressions that he displays with his pseudo-eyebrows.

Normal ("combat body")
Papyrus Overworld Cape Papyrus wears a homemade costume he made with Sans several weeks before the events of the game for a costume party, which he calls his "battle body."[3] According to Sans, Papyrus wears it even when showering.[4] The costume consists of a white chest plate with gold accents, a short red cape, gold-accented gloves, blue shorts with a gold belt, and tall red boots.

If the protagonist continues down the Genocide Route, they encounter Sans in the final corridor. He asks if even the worst personality can change,[15] similar to Papyrus's words before the fight.[16] Without waiting for an answer, he asks the protagonist if they want to have a bad time, warning that if they take another step forward, the protagonist will be very unhappy with what happens next.[17] The game automatically takes this step for the player. Before the upcoming fight, Sans apologizes to Toriel (who is already dead) for breaking his promise to protect a human.

Sans, like his brother Papyrus, uses blue mode in battle. However, he also creates platforms for the player to jump onto and fires skull beams called "Gaster Blasters." Overall, Sans's attacks are much faster and more difficult than Papyrus's, and players consider him the most difficult boss in Undertale.

Sans constantly dodges the protagonist's attacks and counters with relentless attacks of his own, doing everything in his power to stop them. When he approaches exhaustion, he decides to drag out his turn forever, doing nothing and preventing the protagonist from making their own, hoping that he will eventually become bored and give up. However, Sans falls asleep, giving the protagonist the opportunity to approach the BATTLE button without his intervention. When the protagonist attacks again, Sans dodges again, but is immediately hit by a second attack, taking a whopping 9999999 points of damage.

Sans appears several times throughout Snowdin Forest. He sometimes accompanies Papyrus, offers advice on how to counter blue attacks, and observes and comments on his brother's puzzles. Sans doesn't participate in any puzzles except the word search. If his fun value is between 40 and 45, Sans can prank the protagonist by calling them near Papyrus's cardboard post.

Sans Overworld Casino: Before the fight with Papyrus, Sans is absent from Snowdin itself. However, if the protagonist spares Papyrus and goes on a party/date with him, Sans will briefly appear in the Skeleton Brothers' house when the protagonist examines Papyrus's sink and opens the door, causing Annoying Dog to fly out. Afterward, Sans emerges from his room with a trombone and plays a mocking melody. After the party/date, Sans will occasionally interrupt Papyrus's phone calls. In the Xbox One and Xbox Series X|S versions of Undertale, Sans can also appear in the Dog Casino. If Papyrus was killed, Sans cannot be encountered until the final corridor. If the protagonist received OP, Sans gives them time to think about their actions. He then emphasizes the importance of honesty and, if Papyrus is alive, concludes that everything that happens next depends on the protagonist.

If the protagonist killed Papyrus, Sans will ask if he has some kind of "superpower" and if he should use it to do the right thing.[13]

If you answer "yes", he will say: "Then why was it necessary to kill my brother?"
If you answer “no,” he will not judge your point of view, but will call the protagonist a “dirty fratricide.”
Either way, he'll leave after reminding you that Papyrus' death is on your shoulders.

Relationship
Papyrus (younger brother)[1]
Toriel (close friend)
Alphys (Friend) Sans appears several times throughout Snowdin Forest. He sometimes accompanies Papyrus, offers advice on how to counter blue attacks, and observes and comments on his brother's puzzles. Sans doesn't participate in any puzzles except the word search. If the fun value is between 40 and 45, Sans can prank the protagonist by calling them near Papyrus's cardboard post.

Sans Overworld Casino: Before the fight with Papyrus, Sans is absent from Snowdin itself. However, if the protagonist spares Papyrus and goes on a party/date with him, Sans will briefly appear in the Skeleton Brothers' house when the protagonist examines Papyrus' sink and opens the door, causing Annoying Dog to fly out. Afterward, Sans will peek out of his room with a trombone and play a mocking tune. After the party/date, Sans will occasionally interrupt Papyrus' phone calls. In the Xbox One and Xbox Series X|S versions of Undertale, Sans can also appear in the Dog Casino. If Papyrus is killed, Sans will not be encountered until the final corridor.

Hot dog?.. — 30M. Restores 20 HP.
The "meat" is made from something called "water sausage."
Hot Cat - 30M. Restores 21 HP (replaces a second hot dog) - THIS IS HIS FOOD
The next encounter in Waterfall will take place with him at the telescope. He says he's started another business with a premium telescope. Since Sans knows the protagonist well, he'll offer to take a look for free. If you accept, another prank awaits.

Sans is able to dodge the protagonist's attacks, which distinguishes him from other enemies in the game. However, his combat power is quite energy-consuming, and by the end of the battle, he shows visible signs of fatigue, causing him to fall asleep mid-combat. The Gaster Blaster is a weapon Sans uses in battle. As its name suggests, it is somehow related to V.D. Gaster. It is a relatively fast-moving ranged weapon of varying sizes and purposes. Some fire two or more shots. The blaster resembles the skull of a dog- or dragon-like creature, firing laser beams from its mouth. When fired, the lower jaw splits in two. Sans uses it in both standard and blue modes. The beam width directly depends on the blaster's size. During his final attack, Sans uses a large number of blasters firing in a circle. During and after the blaster fires, its eyes begin to flicker. Sans first encounters the protagonist as they exit the Ruins into the Snowdin Forest. As Sans follows the protagonist, their silhouette can be seen passing between the trees in the foreground. He also breaks a heavy branch. After shaking hands, Sans introduces himself and explains that his job is to spot humans, though he has no interest in capturing them, unlike his brother, Papyrus, a man-hunting fanatic (according to him). Sans then hides the protagonist behind a conveniently shaped lamp while Papyrus heatedly discusses his laziness, the importance of puzzles, and his future popularity. After Papyrus leaves, Sans asks the protagonist to show himself to Papyrus, as it will lift his spirits.

Sans is presented as a lazy character, but it is emphasized that this laziness is a result of his knowledge of timelines, and that everything he has worked for can disappear without a trace with a single reset.[7] Furthermore, Sans himself clearly does not consider himself lazy, stating that this is as far from the truth as possible.[8]

Sans appears to have a scientific background, evidenced by his quantum physics textbook, his workshop, his love of science,[9] his unexplained ability to teleport, and his research into timelines.[10] Sans has the ability to use "shortcuts" that allow him to quickly cover large distances in a short amount of time. Sans is also able to appear in multiple locations within a single room at once (as seen in the room leading to the mysterious door in Snowdin Forest), suggesting that Sans has the ability to teleport. Doggo also hints at this when he claims that the skeleton sometimes appears nearby without showing any signs of approaching (this line can be heard if you talk to Doggo at Grillby's Pub after sharing a meal with Sans, or if you ring the bell at Doggo's post repeatedly). Thanks to his "research," Sans is knowledgeable about timelines; Flowey notes that the skeleton has been the cause of most of his resets. His knowledge of timelines makes him more observant, allowing him to detect when the protagonist is acting unusually simply by looking at their facial expression. In the Genocide Route, Sans uses the protagonist's facial expression to determine how many times they've killed them.

Sans once said he doesn't like making promises, but when he does, he tries to keep them to the end. He said the only thing that saved the protagonist from death was his promise to Toriel to protect the fallen.[5] On the Genocide Route, he can no longer keep that promise, but even as he contemplates breaking it to stop a mass murderer, Sans silently apologizes to Toriel.[6]

Sans has a very laid-back personality. He enjoys sleeping, which he does during his breaks at work. He's known for his jokes, which his brother, Papyrus, greatly dislikes. Sans is also kind and friendly. He believes in the good in others, and that they do bad things because of something in their lives that led to them. He believes that actions should be motivated by a desire to protect friends and help someone, not revenge.

Sans is a rather short and "big-boned" skeleton whose hands are very reminiscent of mittens. He is always seen with a wide, toothy grin on his face. Sans wears an unbuttoned blue jacket (or sweatshirt) with a gray hood and a white T-shirt underneath, black shorts with white stripes, and a pair of slippers. His black eye sockets contain white pupils that disappear when he is serious or angry. When using telekinesis, Sans's left eye iris appears, flashing blue and yellow (the colors of patience and justice), while his right pupil disappears.

Sans is one of the key characters in Undertale and Papyrus's older brother. He is first encountered in the Snowdin forest, watching over the protagonist after they escape the Ruins. He serves as a supporting character in the Neutral Route and the True Pacifist Route, and is a heroic antagonist and final boss in the Genocide Route.
If Sans acts sternly at the first meeting and tells you to shake his hand, it will be a prank with a whoopee cushion.