Undertale Yellow: Golden Years.

Clover is a young androgynous human of fair complexion and short brown hair. Official art portrays Clover with yellow eyes.

Clover wears a brown long-sleeved t-shirt beneath a dark brown vest and dark blue pants, presumably denim, girded by a dark reddish-brown belt with a gold buckle. They wear a pair of brown shoes and a light brown cowboy hat with a dark brown hatband. Around their neck, Clover sports a yellow bandana with a blue dot pattern (though some official art depicts it as a checkered blue and yellow bandana).

Clover's background is left ambiguous; however, there are a few hints of their past throughout the game. While never explicitly stated, it is heavily implied that Clover may have an abusive or overly demanding family, that may have resulted in them becoming independent at a young age.

While Clover is largely a silent protagonist (though much less so than Frisk), elements of their personality are shown or implied at several points. In notable contrast with Frisk, most dialogue options for Clover generally depict what Clover is actually saying, as opposed to Frisk where a choice would imply dialogue.

As fitting as the owner of the Justice SOUL, Clover possesses a strong sense of justice, motivated by a drive to do what they perceive to be the right thing. Clover is shown to have an affinity for strange food, in particular having a bizarre taste for gunpowder. Unlike Frisk, Clover does not have the highest amount of Determination in the Underground, so Flowey saves the game on their behalf.

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.

Undertale takes place in a the Underground, just like the Undertale Yellow, under Mount Ebott, where monsters have been sealed by a barrier after losing a war to humans, and are unable to cross through it unless they have seven human SOULs to break the barrier. The story of The Underground begins with the death of King Asgore two childrens — Asriel and Chara… Asriel was a goat monster, and Chara was a human who had fallen into The Underground and was adopted by the king and his wife, Toriel. Soon after, Chara would end up getting sick due to eating poisonous buttercup flowers. They would give Asriel their soul, allowing them to travel onto the surface to collect 6 more SOULs… but due to Asriel being a pacifist, they ended up dying. The king would soon declare war on humanity. Toriel, not being a fan of this choice, would leave him and live within the Ruins. Asgore would go on to collect six human souls, and soon after, a few years later, the seventh human Frisk would fall into the Underground. A little bit of time before this, a golden flower would be injected with a substance called determination… this flower would grow to be known as Flowey, and would adopt a sadistic persona. The human, meanwhile, was a pacifist and would ultimately form friendships with many of the major characters in Undertale. They would end up making peace with the king through their actions, but Flowey would take everybody in the Underground's souls… which ended up reverting him to his true form, “Asriel Dreemurr”. They would face off, but Frisk's overwhelmingly strong pacifist will soon break to Asriel, who would end their rage, and end up using the combination of every monster soul… and the six human souls, to break the barrier that sealed the Underground. He would return the souls to all the monsters and to the humans, bringing them back from their eternal death, and monsters would move back to live on the surface with their happy, true ending.

The mini-comic thread begins with Starlo, Ceroba, and Martlet spending a peaceful evening eating dinner and playing board games. Suddenly, there's a knock at the door. Clover stands there, still hesitant. Several years have passed since the monsters returned to the Surface, and Clover worries that his friends have long forgotten about him, which he shares with Flowey. Flowey simply rolls his eyes, but admits that such a good companion as Clover is truly hard to forget. Unable to bear the doubt, Clover decides to leave without waiting for the door to be opened. At the last moment, his friends notice him, and they all tearfully embrace. Later, Clover meets Kanako, accepts that he must go to school again with his newfound sister, and learns that Ceroba works as a teacher. Everyone begins to live a calm and happy life.

Kanako Ketsukane: Half-Amalgam. Thanks to a combination of the boss monster gene, the soul extract of Integrity, and the infused Determination, she did not merge with the other monsters and continued to fight to maintain her form. Kanako's memories returned as soon as she reunited with Ceroba, slowly regaining her original form. She had to relearn how to walk and talk Regardless, she now has much better control over her body: she can change it as she pleases, most often to pull pranks or scare off bullies. She tends to lose control when she's extremely embarrassed or upset, turning into a shapeless puddle. Ceroba calls this a kind of "Droopy Mode," which helps cheer Kanako up.

Chujin's research was passed on to Alphys in the hopes that it would help other Amalgamates.

Starlo: The town's farmer, responsible for providing food for all its residents. He returned to his parents and now looks after them. He still watches over the town, as his inner sheriff wants everyone to be safe and happy. He continues to hang out with his old gang, occasionally getting them out of trouble. He often transforms into the North Star to cheer up the neighborhood children. The townspeople adore him.

Martlet: A city worker who handles any repairs the city and its residents may require. A self-proclaimed master carpenter, she constantly switches from one task to another and is often distracted by her own carpentry projects and DIY. She regularly spends the night at Ceroba's, much to her delight.

Ceroba: A teacher of monster culture at a city school. Ceroba is adored by almost all the students, except for a few who find her frightening. She built her home on the Surface with the help of Martlet. In memory of her late husband, she wears clothes similar to his old ones. She visits his grave monthly. She does everything she can to move on, accepting the help of her friends. She regained custody of Kanako, helping her recover. She takes on the role of Clover's guardian.

Dalv: A very talented and well-known organist. At least in local circles, and he's happy with that. He lives in a remote corner of town, but tries to get outside as often as possible to get used to his new home... or to take his pet balloon for a spin. Dalv is also unsure whether the sun affects him, so he prefers to play it safe, always carrying a trusty umbrella.

He nearly fainted when he finally met Kanako, learning of her death and revival simultaneously. He completely lost consciousness when Clover appeared... He sometimes joins his friends for dinner.

Clover: He was the last of the fallen children to awaken, regaining his soul. He spent the first few days wandering the Underground, but eventually learned that the Barrier had been destroyed, though several years had passed since then. Despite this, he managed to find his friends and reunite with them. Now he lives with Ceroba as her second child. Having returned to his former life on the Surface, Clover is obliged to attend school again... Still not fully recovered from his own "death," and therefore suffers from nightmares at times. He cares for Kanako like a little sister.

Dina and Hunnie: Dina opened a brand new establishment on the Surface, the Starlight Saloon, which quickly became a favorite spot for everyone. Besides drinks and food, the saloon hosts numerous local talent shows, including evening karaoke, where Kanako has become a true star. It goes without saying that Dina has her hands full and needs an extra pair of hands...

Hunnie, out of work, seized the opportunity and now works part-time, assisting Dina. She's very good at hiding the real reason for her decision to work there, as Hanni really wanted to meet Dalv in person, but Dina finds it amusing and continues to support her.

Feisty Four: Since Starlo decided to take over the family business, the remaining members of the Feisty Five decided to stay and help their new home, just as their former sheriff would have done. Thus, the Flawless Four were born. Each of them found their passion, now helping others enjoy and adapt to the Surface:

Ed Ed became head of security at the Star Saloon. However, troubles are rare enough that he can also serve as an event organizer or simply be there for those in need of a companion.

Moray Moray travels with his trusty guitar, striving to become a musician. He often holds small concerts in saloons. People enjoy listening to his soothing, singing voice.

Ace Ace not only runs various gambling games in the saloon, but is also a highly entertaining illusionist. His signature tricks are matched only by his keen eye for fraud — a gaze that can pierce through anyone who dares to try to deceive the master of illusions.

Mooch In an attempt to start a new life, becomes Ace's assistant in his shows and games. Still a troublemaker at heart.