Ceroba Ketsukane.

Ceroba is a fox-like monster with beige fur. She has long, wavy ginger hair up in a ponytail tied by the Founder's Crest: a red bow with a small gold bell in the center. She has a short white dress, the top of which resembles a kimono, with red trim. She wears a red obi sash tied around her waist and white boots with red trim. Unlike Chujin and Kanako, she does not have a tail. Ceroba's design is inspired by the kitsune, trickster fox spirits from Japanese folklore, correlating with her attempt to trick Clover and take their SOUL. Ceroba is the tallest character in the main cast.

In battle, she wields a brown staff which again has the Founder's Crest, a bright yellow bell in the center of a red bow.

Ceroba appears skeptical and somber upon first meeting her. She acts as a straight man in much of the Wild East's antics, yet still makes the occasional sarcastic joke. She almost never cries; even Chujin only saw her cry twice in the time they were married. She is observant, able to read Clover without them speaking. She also has the ability to tell if SOUL is pure or not, as even in first conversation with Clover. At times, this makes her views more accurate, as she is the only one of Clover's friends who points out that Asgore will kill Clover if they go to New Home; on the other hand, she also holds unrealistic opinions she considers hard truths, such as being convinced that humans will force monsters back Underground once they reach the Surface. She considers Starlo to have not grown up like she did, but expresses some envy over how happy he is.

Call Starlo just by nickname "Star", which she come out when they were teenagers.

When Clover were talking to her in the Steamworks, Ceroba mentions that she considered dating Starlo when she was "a naive kid", suggesting their relationship was a lot closer in the past. She also states her reason for moving on was because she wanted to grow up, and Starlo didn't follow.

Still deeply cares about him despite her choices.

Ceroba is immensely devoted to her loved ones and to Monsterkind. Her devotion turns harmful at times, as she was willing to endanger her daughter and kill Clover for a possibility of fulfilling Chujin's legacy and protecting Monsterkind. She also turns a blind eye to Chujin's negative traits; she always holds him in high regard no matter what information is displayed to her that may say otherwise. She is firm on his legacy as a scientist and a hero of the underground, and she spends the time after his passing trying to complete the work that he had passed down to her.

Despite being observant and calling out others on their beliefs, Ceroba has a habit of hiding her issues and avoiding communication. She does not speak up about Starlo's behavior until after the Feisty Four already called him out on how it was making them feel. Nobody outside of her close circle knows about Kanako falling down, and she avoids sharing further information on it. This manifested strongly in her relationship with Chujin. They had poor communication; beyond Chujin keeping secrets their whole relationship, such as including a secret study in their house and experimenting on himself later, Ceroba and Chujin are implied to not have discussed basic plans for their relationship, such as how many children they wanted. She also lied to and manipulated Clover and Starlo in an attempt to get the former's SOUL, though she is not always good at lying.

Ceroba grew up in the mountains (presumably in or near the Dunes.) She was childhood friends with Starlo. He had a crush on her, and she once considered getting in a relationship with him.
She first met Chujin when she fell into a ditch. She twisted her ankle but considered ruining the crops her mother sent her to get to be worse. Chujin found her after some time and helped her out.

While she describes this as sweet later, a flashback during her boss battle reveals she was driven to tears in the moment, something that Chujin never saw again from her until he was on his deathbed. Despite her commitment to family, this is the only time her parents are mentioned.
They later got married and Chujin built the Estate to raise their family in, though they only ever had Kanako. Ceroba was a housewife while Chujin worked at the Steamworks. After he got fired, he claimed to have retired. He volunteered in Snowdin after this. Their family was financially struggling from the cost of building the estate at this point, so Ceroba had to get a job at Café Dune to support them.
Ceroba did not have much of a life outside of her family. She used to have a gym membership, was acquaintances with Martlet, and would bring Kanako to the Wild East on occasion

Ceroba took care of Chujin as he became sick. He revealed his underground study to her on his deathbed. He died about a year before the game began. After his death, she spent months trying to figure out how to complete his serum without a pure human SOUL. While she eventually came up with a way to, in theory, remove the impurities from an extract from the Integrity SOUL, she still had no Boss Monster to test it on. When Kanako watched Chujin's tapes, she requested Ceroba use the extract on her to make the serum. This failed, causing Kanako to fall down. Ceroba sent her to the True Lab, something she later regrets as Alphys goes silent on updates.

Some time after Kanako fell down, and weeks before the game begins, Ceroba moved out of the Estate and into the Feisty Five's house in the Wild East. She sleeps on the bed, while Starlo takes the couch. She is implied to abuse alcohol during this time.

Fun fact: Ceroba is scared of heights.

Starlo and Ceroba are childhood friends, and it is shown throughout the game they are very close. When talking to her in the Steamworks, Ceroba mentions that she considered dating Starlo when she was younger. She also states her reason for moving on was because she wanted to grow up, and Starlo would not.[8] When Kanako fell down, she moved into the Feisty Five's house with him. He let her sleep on his bed while he took the couch.

Ceroba cares about Starlo's wellbeing, preventing him from killing Clover and destroying his innocence even when Clover's death would assist Ceroba on her mission

Though Ceroba holds some disdain for Starlo's activity of roleplaying, believing it to be damaging to his personality and childish, Ceroba sometimes plays along with the Feisty Five. After the Feisty Four leave him, Ceroba is the one to help Starlo out of his unhealthy behaviour. When she confronts him after the battle, he accepts her complaints, but also reveals his roleplaying was partially to cheer her up after losing Kanako.

During the Pacifist Route, Ceroba refuses to tell Starlo about her plans to finish Chujin's work using Clover's SOUL. She tries to convince him to leave, but when this fails, she knocks him out right before the final boss battle of the Pacifist Route. If she is spared, in the credits, Starlo is shown to cheer Ceroba up by placing his hand on her shoulder, both showing Starlo's attempt to comfort her more maturely and Ceroba being more appreciative of Starlo's efforts to comfort her.

Chujin is Ceroba's late husband. Ceroba took care of Kanako and the Estate while Chujin worked at the Steamworks. After he claimed to have retired after he was fired, Ceroba also picked up a job at Café Dune to support their family as Chujin did volunteer work in Snowdin.

It is shown throughout the Pacifist Route that Ceroba loves Chujin very dearly and is devoted to him. Her devotion is to an extreme. She tries to avoid considering him in any negative light. For example, in the Steamworks, Ceroba shows resentment towards Asgore because of his criticism of Axis despite his criticism being fair and expresses pride over Chujin's award despite it being for his subpar work. She does not mention much of her life outside Chujin and Kanako, and the Estate does not show anything of her life outside them either– in fact, the only part of her house identifiable as hers is her clothes and the Corn Chowder.

Chujin and Ceroba had poor communication. Ceroba and Chujin never discussed Chujin’s work. Chujin directly lied about being fired, claiming that he had retired. He states in his tapes that this was so Ceroba would not think less of him. Ceroba was fully unaware of Chujin's experiments on himself and the Integrity SOUL until he was forced to tell her in an attempt to have her continue his project after his death. Ceroba and Chujin were even implied to not have discussed basic plans for their relationship, such as how many children they wanted.

When he became ill as a result of his experiments, she took care of him. On his deathbed, he informed her of his study in a request to carry on his legacy. In the same scene, he also is regretful over being a burden and requests for Ceroba to leave him behind, though Ceroba firmly rejects this. Ceroba is confident that she has to continue Chujin's legacy, even if it means ruining her own life. She endangers Kanako and accidentally causes her to fall down in the process, and in the Pacifist Route, she is set on killing Clover for his legacy. Starlo and Martlet convince her that she should carry on his kindness instead.

Kanako is Ceroba's daughter. As Ceroba was a housewife, she likely was around Kanako a lot. Ceroba is shown to deeply care about Kanako through dialogue and flashbacks. Before Kanako fell down, the two of them had a routine every night where they would express their love for each other.[18] Kanako also made a mask for her, which Ceroba later uses to transform into her final boss form.

Almost a year after Chujin's death and a few weeks after Clover enters the Underground, Kanako watched the tapes in Chujin's study. Kanako asked Ceroba to use the extract on her to make the serum, trusting that she successfully purified it. While Ceroba was initially reluctant to make Kanako a part of Chujin's plans, Kanako convinced Ceroba to use her SOUL. Kanako fell down soon after Ceroba gave her the extract. This sent Ceroba into a depression, the main cause of her moving out weeks before the game begins and of her drinking.

Starlo is a humanoid monster. His skin is yellow with star-like appendages on his head with light blue patterns on them. He wears a brown poncho with light blue stripes with his sheriff badge on it, brown pants, and black boots with spurs. Starlo has a hat with teal highlights; all members of the Feisty Five have hats and teal highlights in their designs. Starlo carries a gun with him, which is actually a toy. His overworld sprite usually has a smile, but in serious situations he does not have one.

Starlo's true personality is superseded most of the time by a Western persona. Borne out of a fanaticism of Wild Western culture, Starlo puts on this persona from a desire to spread excitement and drama to the inhabitants of the Underground, distracting them from the cruel reality of monsterkind's collective banishment from the Surface. Going by the moniker of "North Star," he plays the role of the Wild East's upbeat sheriff, who is determined to "keep the peace" by any means necessary. This for the most part is all drama, as there is no real danger (besides potentially Clover) and is all put on as a fun distraction for the Wild East's inhabitants, who all mostly seem to play along. While he touts the idea of justice, he uses it as an aesthetic and does not care for deeper moral conundrums, whether disregarding them or only seeing his own perspective.

Starlo values validation from others. He focuses on making spectacles to entertain the townsfolk and enjoys their attention. This is also the reason he eventually attacks Clover: to be revered by the entire Underground.

Starlo's true personality is revealed after his boss fight in the Pacifist Route. He is shown to be much more of a nerd - a picture in his home revealing he was even adorned with stereotypical dweeb braces at one point. His room is filled with various Western memorabilia from the Surface.

Despite this, however, one thing that is constant between "North Star" and Starlo is his kindness and how he values those close to him. In fact, this is the whole reason the "North Star" persona exists in the first place.

Starlo has been friends with Ceroba since they were young children. Starlo used to have a crush on her. When she got engaged to Chujin, he was so devastated that he did not leave the house for days. He has also been friends with the other members of the Feisty Four since high school.

Starlo found western tapes in Waterfall and loved them. He created the Wild East to entertain monsters with a western fantasy. He moved out of his house in the Sunnyside Farm to live with the Feisty Four in the same house.

After Kanako fell down, Starlo let Ceroba live in his house and take his bed.

Starlo is shown to care very deeply for Ceroba, allowing her to stay at his place after Chujin and Kanako left. Part of the reason Starlo overperformed at the Wild East was to distract Ceroba from her worries, though this was ineffective.

Solomon his father.
Crestina is a mother.
And Orion is a brother.

All family members have astronomy-related appearances. Solomon's head has the appearance of a sun and he has an orange mustache. He wears blue farm trousers with a star on them, a white shirt with red stripes, and brown boots. Crestina's head is in a crescent shape and her skin tone is gray-blue. and she wears a red dress, also with a star on it. Orion's head is in the shape of a four-pointed star. He wears blue farm trousers, an orange shirt with black at the end of his sleeves, and brown gloves.

Every Feisty Five member (Ed, Moray, Ace, and Mooch) Starlo included, has a hat and teal highlights in their design. Given that all members of the posse are high school friends, they are close in age.

Ceroba and Starlo are best friends and have known each other since childhood. Starlo once had a crush on Ceroba and was devastated after she got engaged to Chujin. From a picture in his parents' house, it is shown that Starlo was shy around Ceroba when they were teenagers.

Starlo is shown to care very deeply for Ceroba, allowing her to stay at his place after Chujin and Kanako left. Part of the reason Starlo overperformed at the Wild East was to distract Ceroba from her worries, though this was ineffective.

After discovering the truth regarding Ceroba's intentions in the Pacifist Route, Starlo is determined to stop her from following through with Chujin's plan and killing Clover.
However, he still cares for her.

By the end of the Pacifist Route, Starlo has adopted a more mature way of helping Ceroba through her troubles. This is shown by how he helps her up after her boss fight and comforts her during the credits, causing her overworld sprite to smile for the first time.

The Feisty Four are Starlo's close friends, and his partners on Wild East missions. According to Blackjack, they are Starlo's friends from high school, where they shared a club to talk about movies and roleplay - a hobby that they evidently carried into the present together by roleplaying Western scenarios in the Wild East.[4] Outside their missions, the five of them are still very close and all live in the same house. Dina defines their closeness as being "like siblings" or "family" and thus often giving way to petty fights. The fight between them that takes place in the game is apparently much more severe than their usual disagreements.

When Starlo prioritizes Clover and his showmanship over his friends having fun, the Feisty Four all leave Starlo's posse. Moray makes it clear when leaving that an apology from Starlo would fix the situation, however. This proves true in the Pacifist Route during either of which he mentions making up with them (further described as a tearful apology).

Starlo has a distant relationship with his family.

— In his sprites with the farmer attire in the True Pacifist Ending credits, he is referred to as "nerdlo".
— According to his father, Starlo is good at singing, just like his mother and brother.
— It is implied that Starlo may be immune to fire.
– Ceroba has to remind him that most monsters aren't fireproof, and if Clover tells him that the horses survive, he claims that everyone is fireproof.
– Starlo took part in the Actually Magma Smoothie Challenge as shown in the UG Apartments, alongside other mostly fire-based monsters.

Clover falls into a Underground and immediately encounters Toriel, who promises to guide them through the puzzles. However, during one of these puzzles, something goes wrong. The spikes won't open, and Clover falls through the ground. Toriel tells them to stay put while she figures out a way to get them out, but Clover ignores her and goes into the Dark Ruins.

In the Dark Ruins, Clover meets Flowey, who tells him about the Underground and teaches him how to fight monsters. Later, the protagonist encounters a mysterious monster, who talks to himself and complains about interrupting his monologue. After this, Clover finds himself in a maze, which is actually a cornfield. After escaping, he is again confronted by the mysterious monster. He begins a monologue, but this time he stops it as soon as he sees the Clover, then goes home to sleep.

After another dialogue with the mysterious monster, the protagonist finds themselves in a long passageway where they are attacked by Decibat, who, after a battle with Clover, names them Lord of Silence and flies off to spread further silence. After several puzzles, the protagonist encounters the mysterious monster again, who asks them to leave, but Clover continues to follow, prompting the mysterious monster to engage in battle. It is revealed that the mysterious monster's name is Dalv. After the battle, child can enter the house (or it will invite you) where the door to Snowdin is located.
In Snowdin, Clover encounters the Martlet puzzles for the first time, which they must solve along the way. At the very end, Clover encounters the Martlet itself, who, realizing Clover is human, engages in combat, following the Royal Guardian Code. However, the fight turns out to be completely different than she expected, as Clover doesn't attack her, as the code should have. Feeling that she's doing wrong by attacking Clover and receiving no response, she begins asking them to insult her.

However, Clover's insults prove harmless and entirely justified, so she ends the fight. Since the Martlet has violated the Guardian Code, she decides to help Clover escape the Underground without anyone knowing of her failure. She and Clover travel on a boat down the river that is supposed to take them to Hotland. However, the river proves too swift, causing Clover to fall into a cave, and the Martlet to fly away, trying to find help.

After falling, Clover encounters Flowey again, who blames the Martlet for everything that happened and tells her not to trust anyone. After exiting the cave, Clover finds themselves self in the Dunes

Some time later, Clover meets the Martlet again, who promises to help him, but they are forced to split up again when Clover reaches the town of "Wild East." At the entrance, they encounter the "Feisty Five" — Ed, Moray, Ace, Mooch, and North Star. Initially, they want to let the heroes pass, but then North Star realizes Clover is human and decides to forcibly convert him to the "Feisty Five," transforming them into the "Feisty Six." The Martlet tries to stop them from kidnapping Clover, but proves incapable of doing anything and is imprisoned in the local prison.

In the town, Clover meets North Star's friend— Ceroba, who is quite friendly and tells them a little about the "kidnapper." North Star himself begins to prepare Clover to become a member of the Feisty Five, giving them very stupid and easy tasks, which, however, anger the other four members, who had to go through much more serious trials. The climax comes when, after these tasks, North Star appoints Clover as the "city's deputy", a much higher position than that of a member of the Feisty Five, so Ed, Moray, Ace, and Mooch decide to give Clover a "true test" — a battle — while North Star isn't looking. However, he finds out, and a scandal ensues, resulting in North Star's true identity — Starlo — being revealed, and the Feisty Five disband.

The Four say Starlo has changed a lot since he began ruling the Wild East, and Starlo accuses them of envy. After all four leave, Starlo tries to ask for support from Ceroba, who has approached, but she, too, sides with the Four. Starlo leaves and tries to figure out what he needs to do.
When Clover finds Starlo, he initially ponders why his efforts to entertain the Town ended so badly, but when he finds Clover, he first blames them for everything, then decides that if he "does the job of a Royal Guard," he will be respected not only in the Wild East, but throughout the entire Underground. Starlo lassoes Clover and begins a fight. Clover manages to break free, but then Starlo draws a revolver. The last bullet would have surely killed Clover, Ceroba arrives just in time to revive Starlo. Meanwhile, Martlet is freed from its cage, but she hesitates to follow Clover due to being away from her post for too long.

After the encounter with Starlo, Ceroba will accompany Clover to the Steamworks, which introduces new dialogue and slightly alters the progression of the location.
After the battle with Axis, Ceroba and Clover head to the elevator to Hotland, but are stopped by Starlo and Ed. It turns out that while preparing a party to celebrate Kanako's return, they discovered a hatch leading to a bunker containing notes left behind by Chujin before his death. When Starlo asks what Ceroba is planning, she escapes in the elevator, and Starlo chases after her. Before leaving, Starlo orders Ed to take Clover back to the Wild East.
Once back, the others Feisty members show up, with Martlet arriving as well thanks to being contacted by Moray. Martlet convinces Ed to have Clover follow her to Ceroba's old house to investigate while he explains what he knows to the group.

At the estate, they locate the trap door Ed discovered. In the lab, they discover and play the tapes, where it's revealed that Chujin, patriarch of the Ketsukane family, was secretly planning on turning all monsters into Boss Monsters with a fusion of Human and Boss Monster SOULs, to fight another war against Humanity. However, his attempts would fall, and with his dying breath, wanted Ceroba to continue his mission, but to keep Kanako out of the affairs. Horrified, Martlet takes Clover out of the estate and meets up with the Feisty Four, convincing them that she and Clover need to go and stop Ceroba. She flies ahead to Hotland while Clover takes off by foot. Before they can set off, they are stopped by Flowey, who mocks them for trusting Ceroba. However, Flowey then states that he isn't going to stop Clover, and is interested in how things play out.

Clover finds Chujin's gravestone to the northwest of the estate, if they inspect it, they can find a video tape. This video tape reveals that Kanako was with another monster when that monster was attacked by a human, then the human swiftly fled to Waterfall. This enraged Chujin and he sent Axis to neutralize the human, which was done unexpectedly fast, much to Chujin's horrors. He quickly hid the evidence and confiscated the human SOUL for experimentation. This monster is implied to be Dalv, and it is later revealed that this human had the blue SOUL.

At the UG Apartments, Clover follows up and sees Martlet on the rooftop, looking at the CORE. She then explains where Ceroba and Starlo are. Not knowing if she'll get another chance, she states that Clover is a kind person, that despite everything the Royal Guard has taught her, despite being attacked at every turn, Clover choose peaceful solutions every time.

She then promises Clover that after the Ceroba situation is defused, they'll convince Asgore that Clover is a good person and they will be allowed to pass, with the promise of meeting again one day when the barrier breaks. The two share a fist bump before heading back down and through the elevator to the West of New Home.
Once there, they find Starlo and Ceroba in a stand off for Clover's SOUL, and the revelation that there is little hope for Kanako without Clover's SOUL. Despite both Martlet and Starlo's best attempts, Ceroba refuses to back down. Martlet attempts to flee with Clover, but Ceroba knocks out both her and Starlo with little effort. She goes on to state that Clover, while admirable, is naïve for thinking that the five humans can be saved, or that Asgore would let them go. Admitting to be a hypocrite and no better than Asgore on morality, she states she will help Monsterkind by using Chujin's work, stating that if Asgore did break the barrier, humans would defeat them again and stuff them back down into the mountain. She and Clover then fight.

At first, Clover survives Ceroba's attacks, but once brought to the tipping point, she assaults them with a barrage of attacks. Before the last hit can strike, Clover unlocks the Big Shot and blasts back. Realizing the situation, she wears Kanako's mask and takes a kitsune-like form. Clover eventually cracks the mask, which causes a memory to play out before the two of them. The memory is of Chujin on his deathbed, who tells Ceroba of the bunker where he worked on his project, with Kanako having heard everything. Ceroba is initially startled by Clover being in their head, but continues fighting. Clover manages to chip away more of the mask, revealing another memory of Kanako and Ceroba in Chujin's bunker, with Ceroba regrettably deciding to inject Kanako with Chujin's serum, causing her to "fall down".

As Ceroba lays silently before Clover, she reveals how deep her sins are and is "chasing the one ray of sunshine peeking through the surface", unable to let go, and gets up one last time. Eventually, Clover manages to overwhelm and destroy the mask, reverting her back to her normal state. As Ceroba lays defeated before Clover, she eventually realizes her attempts at fulfilling Chujin's legacy costed her family, and made her attack her friends and a child, for something may not have even worked. Racked with guilt, she begs Clover to finish her.
Clover choose to spare her in the end. Ceroba, confused as to why Clover is sparing her, is interrupted by Starlo waking up and brushes off her concerns as payback for how he acted back in the Wild East. Martlet wakes up as well and tries to help Clover escape before Ceroba calms her down by revealing that Clover won. Ceroba then apologizes for how she acted, having been too obsessed in her quest to fulfill Chujin's legacy, before being comforted by Starlo. Martlet also promises to use her Royal Guard connections to the royal scientist to locate Kanako.

After getting up, Ceroba apologizes to Clover for attacking them, stating that what she said back in the Steamworks wasn't false, and spending time with them helped her forget her troubles, with the child walking up and hugging her as an act of forgiveness.

With everything now done, Martlet prepares to take Clover to Asgore and the barrier, but Ceroba shoots it down, stating that Asgore would not care that Clover is a pacifist, and would try to take their SOUL. Martlet, Starlo, and Ceroba all argue as Clover begins to think to themselves. Remembering all they've witnessed in their journey through the Underground, they conclude that monsters have suffered more due to being trapped in the mountain. Clover ultimately decides to give up their plan to rescue the five human children, and instead offers up their own SOUL so that one day, monsters can finally have a future.

Despite Martlet and Starlo's insistence that they don't need to do this, Ceroba realizes that their intent is serious, and agrees to take their SOUL, due to there being no other way for Clover to escape the Underground. The four then share one final hug before Martlet and Starlo leave, with Clover giving them their hat and gun respectively as a farewell present. Ceroba then admits that Clover has gained their respect before extracting their SOUL.

After the deed is done, Clover sends them off before collapsing. Flowey is then heard, expressing his disappointment at Clover becoming "predictable" by sacrificing themselves before stating that while he could RESET everything, he believes that the child has earned their rest, stating that there is always another. Flowey then says his farewells to Clover before leaving, stating that they'll meet again. Clover then crawls up the side of the wall to pass away peacefully.

In Waterfall, Martlet is seen preparing a smaller raft to send Clover off properly, before placing Clover's hat in the raft. As she does so, she reveals she declined a promotion and instead put in her two weeks notice for more productive matters. Just then, Ceroba and Starlo arrive, with the cowboy putting Clover's gun in the raft. Ceroba then reveals that she invited Dalv to join the event, before Starlo then places the Safety Glasses on the raft as well. Martlet then places the raft in the water and sets it off, everyone saying their farewells to Clover. After the last set of credits roll, the raft falls into the Garbage Dump, with the hat and gun landing on a patch of golden flowers.