As a Fridge moments page, all spoilers for Undertale Yellow are UNMARKED. Considering the nature of the game, all Undertale spoilers are unmarked too. Proceed with caution.
- Even in this game, Flowey's metatextual role as a mirror of the player remains. Flowey saw Clover through the Underground on the canonical route many, many times, got frustrated/bored with the results, and decided to introduce a divergence by interfering with the beginning of Clover's journey and taking control of the story's path. Which is to say: Flowey had exhausted the possibilities of canon Undertale, so he made an AU.
- On the Genocide route, why does Martlet not immediately realize that Clover is the one responsible for the panic occurring in Snowdin? As a human gains more LV, they appear to monsters to be less human and more monster — we saw this with Sans trying to introduce Frisk to Papyrus in the Undertale Genocide route. Martlet doesn't realize that Clover is a human because they don't look like one to her — they just look like a monster child.
- On the same topic, why does Clover stop attacking Martlet when she surrenders? Simple: Clover is a justice soul, and isn't fully corrupted by their increased LV yet. All of their other kills could be justified as a matter of self-defense in advance (even against nice enemies like Sweet Corn, Clover is forced into a fight). However, Martlet surrenders and stops attacking. Not only that, but Martlet is still fairly young, and Clover entered the Underground in an attempt to find and rescue the missing humans, at least some of whom are implied to be children. Attacking monsters that are attacking you is one thing, but attacking a young enemy that was trying to protect others — someone just like Clover — who has surrendered? Clover still has some empathy left, and killing Martlet in that position would just be too far.
- Furthermore, even during their final confrontation, rather than just killing Martlet for the heck of it, Clover actually tries to find a justifiable reason to kill her. Which would imply, even with their mind completely twisted by violence at that point, when it came to another soul of justice like Martlet, Clover wanted a damn good reason that justified doing the deed. Not to mention from what was shown throughout the Genocide Route, had Martlet fled again, and stayed out of Clover's way, she likely would have lived.
- Except for Starlo, each member of the Feisty Five is represented by a card suit, which can be seen in the background of their battles: Ed is Clubs, Moray is Diamonds, Ace is Spades, and Mooch is Hearts. Starlo seems to be the odd one out, but there are some five-suit card decks, which often use stars as the fifth suit.
- The prequel kind of explains why Snowdin is so friendly to an invading human like Frisk. Clover's friends have spread tales about "the human of justice" and how some humans aren't evil, they're just really dedicated to an ideal. But deeper into the kingdom, these pro-human tales have to be silenced for fear of royal reprisal, and the tales near the capital are mostly of how Clover managed to best the kingdom's finest champions, downplaying how many they spared.
- After Axis admits to Clover that he killed one of the five humans, Clover's LOVE starts going up rapidly: from 12 to 19, at which point they unleash two attacks: one that destroys Axis' shield, and then a massive laser that vertically bisects the robot. While this rapid increase in LOVE seems strange at first, in Undertale Sans describes LV as "a way of measuring someone's capacity to hurt." In a way, it reflects Clover's feelings towards Axis and by extension the rest of monsterkind: that they all must be punished for murdering the innocent.
- Crosses into Fridge Heartwarming, but Kanako is (as confirmed during an art stream by the developers in April 2024) the Amalgamate that tucks Frisk into bed in the True Lab, should Frisk choose to rest in one. Kanako was shown to be incredibly sweet when alive, she isn't battled anywhere in the True Lab, Amalgamates still retain some level of sentience, and Kanako's theme is called "Tucked In".
- Undyne readily hires Martlet as a Royal Guard, yet in Undertale, she refuses to hire Papyrus on the grounds of him being too kind. Why? She learned from her mistakes after Martlet resigned due to seeing the darker elements of what her job entails.
- Ceroba's theme in the second half of her pacifist battle is "A Mother's Love". While one would assume that it's just referring to revelations regarding her and her family, in the context of Undertale, LOVE stands for "Level Of Violence", or one's willingness to hurt someone. In other words, "A Mother's Love" refers to Ceroba's willingness to kill an innocent child in hopes of saving her own.
- Flowey meets his end in the genocide route after admonishing Clover for their vigilante actions. He tries to reassert his power, only to be met with a threatening death glare from Clover. When he tries to override Clover’s save file he is unable to because of how quickly Clover keeps loading their current one, much to Flowey’s increasing horror. In other words, while Clover lacked Chara’s determination, as a battle-hardened gunslinger, they’ve now become an expert at re-LOADING.
- As per his hidden log, Chujin was highly disturbed at the sight of Integrity's death at the hands of Axis. Of course, this could be easily interpreted as him being a monster and not being used to human bodies just staying there after death as opposed to turning to dust, as well as, you know, seeing a child's dead body. But some of the hidden RUIN's graffiti that appears if the player has a specific FUN value appears to tell the entire story of the Blue SOUL if pieced together… and shows a crude illustration of Integrity with a scorch mark where their head is and what appears to be pieces of something just above it. If that's how Integrity died… yeesh.
- After dying, from what was heavily implied to be a pretty gruesome death, the details within the "Mysterious of the Underground" book, and Chujin's logs, reveals that Integrity's SOUL was held captive by Chujin for several years, during which time he had made multiple attempts to fuse their SOUL with his own, and when that proved to not go as planned, moved on to other forms of experimentations, which eventually lead to the Serum. Considering Chujin had Integrity's SOUL for several years, one has to wonder what exactly he did to their SOUL to create the serum in the first place, and as his logs reveal he had experimented on their SOUL several times over the course of that time… how many of these experiments had he actually performed on Integrity's SOUL before he was satisfied?
- Given how Asriel and Chara shared a body when Asriel absorbed the latter's soul, one could only wonder what's going on in Asgore's head seeing himself in the body of his killer as they exit the Underground with his people's only hope of escape during the end of the Genocide run.
- On that note, thing's don't look too good after the Genocide Route.
- With Clover having escaped the Underground with the human souls, there's no doubt that people will learn of what happened to the missing humans. This itself could lead to the Underground being stormed — presumably by soldiers with no intention of showing mercy.
- Unless measures are taken to prevent people from doing so, Frisk will be entering a much more hostile Underground not helped by the lack of any escape, what with Flowey being dead and there being not enough souls of humans and monsters to break the barrier even if he was still around.
- If Ceroba had actually succeeded in acquiring Clover's SOUL, and fused it with Kanako's to save her from her Fallen Down state, not only would Clover and Kanako end up sharing a body, which would be pretty overwhelming for someone as young and innocent as Kanako to deal with, as well as the fact she would now possess power that she would have no idea on how to handle. But Ceroba who at this point hadn't been convinced to let the past go, would have doubled down on her mission to continue Chujin's legacy, and likely would've tried to use Kanoko to try and finish his work, potentially ruining her daughter's life again, in her single-minded obsession to finish what her husband started.
- Clover and Kanako sharing a body, also means that Clover's influence can affect Kanoko's decisions, and considering Clover's SOUL would be pure, meaning they wouldn't have any ill intentions towards anyone, it is very likely Kanoko would be very much against what her mother is doing despite her love for her, as she would see the injustice of her actions because of Clover's SOUL of justice. In other words, fusing their SOULS together, would likely end up working against Ceroba rather than for her, and by not thinking things through, she would have created another problem that would be far beyond her capabilities to handle.
- The Neutral Route reveals that Clover has no memory of any of the Resets that Flowey does. However, if one takes into consideration what happens in the Genocide Route, where Clover overpowers Flowey's ability to SAVE and LOAD, while also being the one who can RESET afterwards, it really makes you wonder how clueless Clover really was. This of course delves into the very likely possibility that rather than it being the case of Clover being manipulated by Flowey again and again during the alternate pathway in the Underground, because they have no memory after a RESET, they were in fact fully aware of what was happening, and was trying to find an outcome that satisfied them, rather than Flowey.
- Chujin told Ceroba in the tapes not to get Kanako involved in this. Ceroba then proceeded to get Kanako involved in this. In the text Kanako takes a single conversation to overturn Ceroba's devotion to her husband's wishes. (This can be partially patched by assuming it took far longer than one conversation. Perhaps Kanako was doing this over years?)
Both of the game's Pacifist endings can make the Neutral and True Pacifist endings of Undertale far more depressing.
