Characters / Undertale - Spoiler Characters

Undertale Main Character Index
Major (The Human Child, Flowey, Sans, Papyrus, Undyne, Mettaton, Asgore Dreemurr)
Others | Monsters | Spoilers (The Fallen Human)

As the name indicates, everyone on this page is a Walking Spoiler, even more than the already spoilery main characters. Even their very existence is a major plot twist. Thus this page contains no spoiler-marking at all. You Have Been Warned. You wouldn't want a bad time, would you?

Character-Specific Pages

• Asriel Dreemurr^note As a subpage of his present identity
• The Fallen Human

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General

• Walking Spoiler: All of them are this, as it's very difficult to talk about them without spoiling key details of the game.
  • The six human souls play a crucial role in beating a major boss. Problem is, that boss is built around trying to make you feel hopeless, so if you know how to beat him going in, the effect is ruined.
  • Asriel, and in particular his existence as Flowey, spoils the pacifist and genocide endings.
  • The Amalgamates spoil much of the pacifist ending since they are only found in the secret area known as the True Lab, where Flowey was created.
  • Chara/The Fallen Child spoils the Genocide ending, and to a lesser extent the Pacifist and Neutral endings as well. Turns out the child from the opening movie isn't the character you're playing as, and in a Genocide run, that first Fallen Child destroys the world.
  • You, as in, being a separate entity from the actual player character, spoils the fourth wall breaking aspects of the Pacifist and Genocide endings.
  • W.D. Gaster and his followers are characters hidden in the game's code with an unclear identity. Some content related to him resides within (or is related to) late-game content in both routes. Granted, you aren't really expected to find him yourself anyway.

Human SOULs

Human SOULs

"Seven. Seven human souls, and King ASGORE will become a god.
Six. That's how many we have collected thus far."

The six humans who fell down into the underground before the Player Character did. Their SOULs were harvested for the sake of breaking the barrier imprisoning the monsters and exterminating the human race. You can find their old weapons and armour scattered throughout the world.

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General tropes

• And I Must Scream: They're seemingly unable to do anything while they're trapped in the SOUL jars.
• Ambiguous Gender: Like Frisk and Chara, their genders are never revealed.
• Ambiguously Evil: One of them (the blue SOUL) likely killed at least one monster, possibly more, but we have no idea why or how.
• Asshole Victim: Maybe some of them. It's implied that at least a couple of them managed to rack up a lot of EXP and some LOVE before they were killed, most prominently the blue soul (whose items are described as "dangerous" and covered in dust^note what monsters turn into when they die) and the yellow soul (who had a real gun). It's left ambiguous, however, if they did this for actually malicious reasons, or if they did it out of (legitimate, since unlike the player character, they only have one life) self-defense, or a desperation to avoid being killed and forcibly used as a weapon to destroy everyone they love.
• Barred from the Afterlife: Forced to stay rooted in the mortal world after death through unexplained technology. In the Neutral and Pacifist endings, they're all finally set free.
• Big Damn Heroes: After calling out to them enough, they resonate with Frisk and begin turning the fight against Flowey. And when he uses his save state powers to undo his defeat, they unite to utterly destroy him in one shot, saving Frisk from a truly unwinnable situation.
• Colour-Coded for Your Convenience: Separately from your red SOUL and white monster SOULs; they come in orange, yellow, green, cyan, purple, and blue. Notably, the colors correspond to the various colors that bosses can turn your SOUL, as well as the three different attack colors. In addition, the colors are indicative of the humans' greatest virtue before they died: Cyan - Patience, Orange - Bravery, Blue - Integrity, Purple - Perseverance, Green - Kindness, and Yellow - Justice.
• Determinator: The purple SOUL's special trait was perseverance. Though obviously they weren't as determined as Flowey or Frisk. In fact, all of the SOUL traits are implied to be their own source of DETERMINATION.
• Empathic Weapon: Even after death, they can still feel emotion and respond to your fight against Flowey.
• Everyone Has Standards:
  • Despite their rather unclear morality, all of them aid you during the battle against Flowey and eventually rebel against his control to save you.
  • Also, one of the rare things that's sure about them is that they all met Toriel in the Ruins. Since she's still there at the beginning of the game, none of them harmed her. Therefore, even the more morally ambiguous of them never thought of harming her, let alone doing a Genocide Run.
• Fatal Flaw: Can be inferred, judging by the location and effects of their equipment and/or their SOUL modes. First of all, it's implied that none of them had enough Determination to LOAD or SAVE, meaning they only had one life to live. Once they died, that was it.
  • Cyan: Cyan attacks in the game are dodged by standing still, implying that a cyan-colored SOUL won't move or dodge attacks. Cyan's journey was the shortest, and their equipment is found in the Ruins, the earliest part of the game. That, or they were too patient. They waited in place absolutely sure that they'll be saved and starved to death.
  • Orange: Orange attacks are dodged by moving through them. An orange SOUL would be constantly moving around and unable to dodge cyan attacks, which are used by the guard dogs in Snowdin. Additionally, the Ball Game mentions them "rush[ing] fists-first through all obstacles", implying that they were reckless and got in over their head, leading to their death.
  • Blue: A blue SOUL is affected by gravity and can only make short jumps before falling to the bottom of the bullet box. Many enemies in Waterfall, where Blue's equipment is found, have attacks that are difficult to dodge at the bottom of the box (Aaron's CHECK text even says as much).
  • Purple: Their equipment increases invincibility after taking damage, requiring them to get hit in order to make the best use of their weapons. They likely allowed themself to get hit too many times and died.
  • Green: The green SOUL mode makes the player's soul immobile and allows them to block attacks from a single direction. Their equipment is found in Hotland, where there are multiple enemies (Pyrope, the Royal Guards) whose bullets come from all directions. Even then, their equipment's perks also suggest that they were over-reliant on healing items mid-battle and likely ran out of supplies at the worst possible time.
  • Yellow: They had a gun for a weapon and possibly made it the farthest (along with Green), but it's empty when the player gets it, implying that they lost their last line of defense when they ran out of bullets. Whoops.
• Hero of Another Story: Or Villain of Another Story, depending on whether or not they (or some of them) actually were evil. They fell into a predicament similar to Frisk's and, just like them, they went on a quest to try to go back in their world. However, they are already dead when the game begins, leaving behind them a few items and very few clues on what their stories were.
• Human Sacrifice: They were killed to make someone powerful enough to break the barrier.
• Improbable Weapon User: Including ballerina shoes, a notebook, and a frying pan.
• Killed Off for Real: They fell in various points during the Underground, it's implied the farthest any of the other souls made it was Hotland (the green and possibly the yellow one, depending on where Catty and Bratty got the yellow SOUL's equipment from).
• Leitmotif: Within the song "Your Best Nightmare," a different remix of "Your Best Friend" for each of them plays when they are fought during the confrontation with Photoshop Flowey. Cyan's and Orange's versions are higher-pitched than the original, Purple's and Yellow's versions are lower-pitched, Blue's uses a whistle instead of chiptune, and Green's uses a piano.
• Living MacGuffin: All of them were this at one point, because the monsters need seven human SOULs to break the barrier. Played with by the time the game starts because while their bodies have perished, their souls are still around and carefully contained.
• Mysterious Past: All that is known of them are the weapons and armor they left behind and what can be inferred from the color of their SOULS. How and why they ended up in the Underground, how they died, and even if they were children like Frisk and Chara are completely unknown.
• Our Souls Are Different: Humans in life, unlike monsters, are mostly physical matter, making them generally much stronger than an equivalent monster. Their colored SOULs linger after death whereas monster white SOULs vanish instantly (apart from those of 'boss monsters' like Toriel and Asgore). This asymmetry on their natures means it's almost impossible for a human to absorb a monster's SOUL but a monster can easily consume a lingering human SOUL, and use them as an immense power source. Absorbing just seven SOULs (of which are obviously plentiful in supply) (possibly) negates any Assimilation Backfire and would make that monster become God-like. When Monster-Human relationships deteriorated in the prologue, and a war happened, monsters lost. After the war eventually culminated in the banishment of monsters into the underworld, the despairing monsters can only hope their king one day acquires enough SOULs to shatter the barrier.
• Plot Coupon: They're six differently colored (but otherwise identical) objects that are being collected in order to accomplish a goal, which clearly resembles a common type of plot coupon in RPGs. The difference with these? You're not collecting them; the monsters are, and the player character happens to be the last one they need.
• Posthumous Character: All of them died and their souls were taken by Asgore before the game began; the exact circumstances of their deaths, either at the hands of Asgore himself or someone else, isn't stated.
• Rainbow Motif: Together with Frisk's red heart. This also pops up in with 7 coffins with the same color hearts (with the red one being closed), and with Photoshop Flowey cycling through the entire spectrum in his demise.
• Riddle for the Ages: Why did they climb the mountain and fall into the Underground, what were their personalities like, and how did they die?
• Ripple-Effect-Proof Memory: Them having this is the only saving grace in the Photoshop Flowey fight. Even if you die and Flowey reloads, they remember that you've called to them, and they still want to help you. This contributes to them rebelling after you "defeat" Flowey and he reminds you that he can just reload back to full health.
• Shout-Out: Much like Frisk's Stick, their weapons, with the exception of the Torn Notebook, belong to classes of Mother weapons:
  • Toy Knife: Teddy from the first game had knives as his first two weapons, though these would be outshone by a Sword and Katana.
  • Tough Glove: Kumatora from the third game used gloves.
  • Ballet Shoes: Duster from the third game would kick with his shoes, though none of them were ballet shoes.
  • Burnt Pan: Ana and Paula from the first two games fought with frying pans.
  • Empty Gun: Lloyd and Jeff, also from the first two games, wielded guns.
• Sentient Phlebotinum: As they're the souls of humans who double as a source of immense power they naturally qualify. This saves you against Omega Flowey when you get them to help you.
• Take Up My Sword: All of the Gear in the game, with exception to the Temmie Armor and the items in New Home were gear used by them before they died. In the battle against Flowey, it is even shown in attack phases which colored soul used which weapon:
  • Cyan = Toy Knife and Faded Ribbon
  • Orange = Tough Glove and Manly Bandanna
  • Blue = Ballet Shoes and Old Tutu
  • Purple = Torn Notebook and Cloudy Glasses
  • Green = Burnt Pan and Stained Apron
  • Yellow = Empty Gun and Cowboy Hat
• Triumphant Reprise: After reaching all of their hearts by calling for help, "Your Best Nightmare" changes from a terrifying to a joyous remix of "Your Best Friend" during the Photoshop Flowey battle's final phase.
• Unknown Character: Despite their importance in the story and the Neutral and True Pacifist Endings, almost all information on them is either implied or completely left for interpretation. Even their names are unknown, as in the room with their coffins, only Chara's can be read^note each coffin is as long as the room's width; Chara's is "blocking" the other six.
• What Happened to the Mouse?:
  • They're mentioned as missing in the Neutral and True endings, but what happened otherwise is unexplained. Simple Logic would state that in a Neutral ending, the only person there is Frisk, and Humans cannot absorb Human souls, nor can Monsters absorb Monster souls. In the True Pacifist ending, Asriel says that he can't bear to keep the souls imprisoned within him, and lets them all go, the six human souls included.
  • If you return to the room with the coffins at the end of the True Pacifist route, you find that they're all now open. Make of this what you will.
  • In the Genocide ending, Undyne states that Asgore will absorb them to crush the Villain Protagonist, but he never actually does so, and Flowey doesn't take them either. They never do actually make an appearance.

Cyan SOUL

Patience is a virtue.

• Deliberately Cute Child: The Faded Ribbon adds +5 defense and has the flavor text, "If you're cuter, monsters won't hit you as hard."
• Heart Symbol: The bandage-shaped healing bullets they send you have hearts on them.
• Hope Spot: Possibly implied — there is a message in the CORE that implies the cyan SOUL may have made it farther then some think. The message reads, "(I cannot fight. I cannot think.) (But with patience, I will make my way through.)"
• My Little Panzer: The Toy Knife, a knife made of plastic, which is said to be "a rarity nowadays."
• Psycho Knife Nut: Their weapon was a plastic toy knife, and Photoshop Flowey uses them to throw knives at you.

Orange SOUL

Take risks and be brave.

• Body Motifs: Hands. Their weapon is the Tough Glove, their standard attack animation uses fists, the Ball Game describes them rushing "fists-first through all obstacles," their attacks during the Photoshop Flowey fight consist of multiple hands, and their healing bullets are shaped like hands making the thumbs-up gesture.
• Fearless Fool: A reckless child who ran straight into adventure and danger, and unfortunately did not make it very far.
• Heart Symbol: The hand-shaped healing bullets they send you have hearts on them.
• Hot-Blooded: Their associated trait is Bravery, and the flavor text in the Ball Game says, "You are the kind of person who rushes fists-first through all obstacles."
• Leeroy Jenkins: The Ball Game's flavor text implies them to have been reckless, and they only made it as far as Snowdin before dying.
• Power Fist: The Tough Glove, "a worn pink leather glove for five-fingered folk."

Blue SOUL

Integrity is choosing courage over comfort.

• Action Girl: They're implied to have been a ballerina based on their clothing, and they certainly were a fighter.
• Ambiguously Evil: The Old Tutu is described as being covered in dust (which is what monsters turn into when they die) and the Ballet Shoes make the player feel "incredibly dangerous" after putting them on. Thus, it's implied that their owner used them to kill at least one monster, possibly more. However, it's not known if they did this out of maliciousness or simply self-preservation, since the monsters were also trying to kill them. It's also possible the dust did not originate from any monster, instead it gathered naturally from being abandoned over the passage of time.
• Dance Battler: Implied to be one, based on their armor being a tutu and their weapons being ballet shoes.
• Giant Foot of Stomping: During their attack phase in Photoshop Flowey's battle, the player has to dodge a horizontal row of ballet shoes stomping on them, toe-first.
• Music Is Eighth Notes: During the Photoshop Flowey fight, they heal you with a row of green eighth notes.

Purple SOUL

Take notes and keep on persevering.

• Awesomeness by Analysis: Their strategy for surviving in the Underground was to take notes on all the monsters they battled.
  Ball Game, purple text: Even when you felt trapped, you took notes and achieved the end of "Ball."
• Eye Motifs: They wore a pair of glasses and their notebooks during the Photoshop Flowey fight have open eyes on them.
• The Illegible: Their handwriting was apparently terrible, if the Torn Notebook's description is anything to go by.
• Lethal Joke Item: The Torn Notebook, which "contains illegible scrawls."
• Logical Weakness: Their items increase Mercy Invincibility for a longer period of time, which means you have to deliberately take damage in order to make the best use of them...which will not be easy on a True Pacifist playthrough, since you'll never be able to get above 20 HP.
• Mercy Invincibility: Both the Torn Notebook and Cloudy Glasses increase the INV stat, which determines the number of frames that an attack can't hurt the protagonist after they receive damage. In-game, the only other item that can do this is the Temmie Armor.
• Nerd Glasses: Their armor was the Cloudy Glasses, and they seemed like a nerdy, bookish type of person.
• Words Can Break My Bones: During Photoshop Flowey's fight, they initially attack you with negative words like "HATRED," "RUIN," "MURDERER," "DESPAIR," "TERROR," and "DESTROY." Calling for help changes them into positive words like "LOVE," "FREEDOM," "RELIEF," "MERCY," and "CREATE." Their final healing bullet is the word "HOPE."

Green SOUL

Kindness makes the world go round.

• Chef of Iron: Their weapon was a frying pan and their armor was an apron.
• Frying Pan of Doom: The Burnt Pan, whose "damage is rather consistent" adds +10 AT and heals 4 more HP every time a consumable item is used.
• Heart Symbol: The Stained Apron's overworld sprite shows it to be decorated with a heart.
• Luckily, My Shield Will Protect Me: The green SOUL mode allows the player to block bullets coming from four directions, thereby implying that the green SOUL used their frying pan as a shield.
• Nice Guy: Their associated trait is Kindness.
• Playing with Fire: Getting past them during Photoshop Flowey's fight requires dodging waves of flames tossed from three frying pans.
• Power-Up Food: When turned to Frisk's side, they send out healing bullets shaped like fried eggs.

Yellow SOUL

For truth, justice and the human way.

• Cowboy: Implied to have been one based on the Cowboy Hat and gun that resembles a standard six-shooter.
• Flower Motifs: Their healing bullets are shaped like four-leaf clovers. Maybe they're wishing you good luck against Flowey.
• For Great Justice: Their associated trait is Justice.
• The Gunslinger: The only one of the humans to use a conventional weapon — in their case, a real gun.
• Hope Spot: They made it the farthest of all the humans who came through the Underground...but in the end, they still died, just like those who came before them^note That being said, Bratty and Catty, the people who sell you the Yellow Soul’s equipment, mention they found it in the Waterfall dump, implying either they didn’t get as far as Hotland or their gear was disposed of after dying to Asgore or someone else near the CORE.

The Amalgamates

The Amalgamates

no No NO NO NO NO NO^note from left to right: Endogeny, Lemon Bread, Reaper Bird, Crystaldrake, and the Memoryheads

Alphys, in a bid to test a potential way to escape the underground, decided to inject dying monsters with Determination and see if it would be able to save them. While it seemed like a failure at first, eventually the monsters woke up like nothing happened… until they began to melt. Monster bodies are unable to properly handle Determination, and as such their bodies broke down to the extent that they began to fuse together into horrifying abominations unable to die. Now they live in the True Lab, hidden by Alphys out of guilt and shame, unable to return to their families and acting as a permanent reminder of Alphys's failure.

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• Alien Geometries: Assuming its sprite is meant to be taken literally, Endogeny appears to somehow have a series of dog faces and bodies in the negative space between its legs.
• And I Must Scream: All of them (especially Lemon Bread) are at least slightly aware of their plight, but they can't do anything about it due to Alphys keeping them a secret, and they can't die by normal means.
  Lemon Bread: Welcome to my special hell.
• Assist Character: The Reaper Bird doesn't attack directly; it instead has the help of "Everyman", a bird-like humanoid that attacks in bizarre ways.
• Big Friendly Dog: If you coax Endogeny over, you can pet it like the other dogs. It's described as being very affectionate in some of the quotes.
• Black Speech: Although they become less unintelligible later into their battles.
  • The Memoryheads will display glitchy and rapidly-moving black boxes in their speech bubbles to the sound of dial-up internet. This stops when you begin using your cellphone, causing them to speak normally.
  • Reaper Bird speaks with three speech bubbles stacked on top of each other, creating an almost-unreadable mess. After using the ACTs according to the component monsters, the speech bubbles separate and can be read normally.
• Blob Monster: Endogeny is described as being amorphous, and is a vaguely dog-shaped blob that can disperse itself into floating particles. Much of the other Amalgamates tend to be more Downplayed cases, having a sort of "melting" effect from the experiments and having the ability to shapeshift. However, Lemon Bread is a straighter example as one of their components is Moldbygg, a type of slime.
• Body Horror: Several "normal" monsters combined into one, rearranging each other's typical features in unnatural ways (such as Lemon Bread using two copies of Aaron's tailfins as eyes and Reaper Bird stretching a Final Froggit's body into wings).
• Call-Back: By the time you face them, you'll likely have faced all of their "components" earlier in the game. The method of Sparing them tends to be similar. Special mention goes to Endogeny, whose Spare method is exactly the same as that of Greater Dog. Once it's pacified, the background music changes to "Dogsong", which played in the fight against Greater Dog.
• Came Back Wrong: The result of Alphys' experiments with injecting monster souls with Determination.
• Creepy Good: They're terrifying to look at, the reason behind their existence is horrifying, and the sequence in which you meet them is probably the closest the game ever comes to being a straight-up horror game… but none of them seem to sincerely want to hurt you (outside of maybe Lemon Bread, and even then that's more you being the first target for… their… frustrations in years), they all back off once Alphys tells them to, and at the end of the pacifist route, their happy ending is simply being with their families again. They're creepy, sure, but not truly malevolent, or are only truly dangerous should you panic and not attempt to understand them.
• Dark Reprise: Unlike the other Amalgamates, which use the Drum and Bass track "Amalgam" as their battle theme, Endogeny and Crystaldrake are respectively fought to heavily distorted versions of the goofy "Dogsong" and the tranquil "Snowy".
• Detachment Combat: The Reaper Bird's Everyman can send its head flying at your SOUL. Actually, make that about a dozen heads at once.
• The Dividual: Memoryheads appear in-battle as three different enemies, but you can simply spare them by interacting with one, with the rest following. They also identify as a collective, asking you to join them.
• Dual Boss: The Memoryheads are a triple boss, but in practice it's just one enemy, as you can't kill them and they're all Spared at the same time.
• Expy:
  • Lemon Bread has a similar name and design to Melon Bread, a boss from the Genesis game Gunstar Heroes. One of Lemon Bread's attacks even mimics Melon Bread's appearance.
  • The Memoryheads resemble Giygas.
  • As a whole, they are amalgamates of references to the chimeras from Mother 3.
• Eye Scream: Crystaldrake has Vegetoid faces in the place where her eyes would be. Similarly, Reaper Bird's eye is also Astigmatism's mouth.
• Facial Horror: Their faces are just horrendous to look at simply because of how distorted they are.
• Feathered Fiend: The aptly-named Reaper Bird Amalgamate is just one of the many who attack you in the True Lab. Ironically, it has no bird monster as a component whatsoever (not like there are many of those in the Underground to begin with).^note It's made of Final Froggit, Whimsalot, and Astigmatism.
  • Painfully subverted with Snowdrake's mother; she also attacks you in the True Lab, but her attacks are so ineffective some of them don't even go into the board.
• Final-Exam Boss: Hopefully you remember how to spare the monsters in the previous areas; you'll need to if you want to get past these guys.
• Frankenstein's Monster: Are quite similar, such as being the result of an experiment to cheat death, being composed of multiple corpses, and their creator being horrified of what she created. Unlike the original one, however, they ultimately get a happy ending.
• Genetic Abomination: Although ultimately Lovecraft Lite, their powers are definitely more on the Eldritch Abomination end of the fence. Their encounters play out like video game glitches, with bizarre names and strange dialogue. The Memoryheads' ACT options are your menu buttons until you use the "CALL" command. The Reaper Bird's flavor text and dialogue is multiple overlapping lines of text, and is initially only called ",". Yes, just that one punctuation mark. Lemon Bread's dialogue comes from 12 separate speech bubbles covering the top of the screen. If you try to ignore Endogeny, the flavor text says he appears everywhere you look, and trying to talk to Crystaldrake will often result in the dialog box describing you as doing things much more extreme than the command suggested.
• Gone Horribly Wrong: They originated as an experiment by Alphys to infuse comatose, nearly-dead monsters with Determination. To say it didn't go as planned is a gigantic understatement.
• Gone Horribly Right: Part of the purpose of said experiment was to save said monsters' lives, which did happen… but at a terrible cost.
• The Grotesque: Despite their horrific appearances, they turn out to be no more violent or evil than any other enemy you've faced throughout the game. Alphys eventually decides to quit keeping them a secret and lets them join the other monsters in the Underground, where they seem to get along peacefully enough.
• I Am Legion: While the Amalgamates are all combinations of different monsters combines into a collective consciousness, the Memoryheads are the most significant case in that they refer to themselves as "us" every time they offer a chance to "join" them.
• Interface Screw:
  • Trying to attack any of them leads to a mess of red words popping up over them instead of damage numbers. In the Memoryheads' case, it causes their health bar to extend past the box when checked again.
  • Reaper Bird extends itself past the battle screen and over the dialogue box.
• Knight of Cerebus: Their appearance marks one of the darkest and scariest segments of the game and its backstory. Fortunately, none of them are truly evil.
• Lovecraft Lite: While they are quite horrific to look at and possess bizarre glitch-like abilities, they won't drive you insane when you look at them and are further disqualified from full Lovecraftian status by, well, being rather nice once you get to know them. The Memoryheads especially tell you to "Come join the fun", but when you refuse they just say "Oh well" and "It's a real get together" and leave you in peace. Heck, if you decide to sleep in one of the lab's beds, an amalgamate (not pictured) will tuck you in and pat you on the head.
• Man Bites Man: Lemon Bread's primary method of attacking you is by distorting the bullet board into their fanged mouth and using it bite down on the soul.
• Meaningful Name: Lemon Bread is named after a type of pudding, and one of its constituent parts is Moldbygg, a gelatin monster. Also, they smell like lemons for some reason...
• Merging Mistake: Essentially, the determination that revived these monsters was too much for their magical bodies and it caused them to melt. And when they tried to help each other, all they did was accidentally stick to each other. Fortunately, they all seem to be mostly comfortable with their new state of being.
• Mind Screw: The Amalgamates are capable of messing with the battle interface, replace their damage numbers with a collection of fast-moving words, and can somehow shapeshift into in-game mechanics, such as Lemon Bread disguising as a SAVE point and Reaper Bird appearing in your "!" speech bubble.
• Missing Mom: It turns out Snowdrake's mother ended up as one of the Amalgamates after she fell down. Thankfully, she's reunited and accepted by both Snowdrake and his dad by the time you reach the true ending.
• More Teeth than the Osmond Family: Lemon Bread, whose teeth are actually made up of pieces of a Moldbygg. Their face consists of two angry eyes (which are Aaron tails) and a huge mass of gelatinous teeth. Their attack also consists of lots of teeth trying to crush your SOUL.
• Mythology Gag: In The Halloween Hack, another one of Toby Fox's games, a trio of minibosses replacing the Krakens called the "Amalgamates" shows up in the late-game, and has the same base idea as the Amalgamates in this game (several monster parts combined to create one new monster). However, the Amalgamates in Undertale are important to the story, rather than generic baddies, though both are the last set of minibosses before the Final Boss.
• Named by the Adaptation: Deltarune gives the names of several of the Amalgamates' components before they became what they are. Snowdrake's Mother is named Crystal, one of the dogs in Endogeny was named Muttler, and Shyren's sister in Lemon Bread was named Shyra.
• No Biological Sex: Ambiguously either played straight or Inverted. Many of them are composed of both men and women, such as Lemon Bread, who is both Shyren's sister and Aaron's brother. The game never elaborates on how (or whether) this works out.
• No-Sell: They're completely unable to die^note by normal means at least: trying to attack any of them just causes red text to quickly flash by, bragging about the attack being ineffective, instead of damage numbers, and the HP bar of the one you attacked extends beyond the dialog box afterwards. Fortunately, this means you can't ruin your Pacifist run by accidentally killing one. While Snowdrake's Mother does take damage from attacks normally, she's still effectively unkillable as her health regenerates at the start of each turn.^note She can be killed if you hack your ATK to the maximum value, but she's worth no EXP, as this clearly wasn't intended to be a possible outcome of the fight.
• One-Letter Name: In-battle, Reaper Bird's name is rendered as a single comma.
• Our Zombies Are Different: They are essentially undead monsters. Well, not in the same way as the skeleton brothers and ghost cousins, but you get the idea.
• Permafusion: They're the end result of a botched experiment involving multiple monsters and DETERMINATION, with the latter causing the former to basically melt into each other, creating each individual Amalgamate.
• Poison Mushroom: The Memoryheads can give you a Bad Memory if you perform the Item ACT on them. It damages you for 1 HP if used, but it's a full heal at critical HP.
• Punny Name: Endogeny. It's comprised of the parents of the Royal Guard dogs. And then some...
• Recurring Extra: Reaper Bird's Everyman, named "strangeman" in the game's files, has a few suspicious appearances in Deltarune — as a cameo in two boss fights (the Superboss' carousel attack in Chapter 1 and Queen's social media attack in Chapter 2), one regular enemy fight (a pop-up window in one of Poppup's attacks), and as graffiti in the Light World. Toby Fox referred to him both on Twitter and the artbook as "Just a good guy that shows up on occasion", as if suggesting some kind of importance…
• Say My Name: Snowdrake's mom is constantly calling out for "Sn… o… wy…"
• Treacherous Checkpoint: Lemon Bread is disguised as a Save Point until you interact with it. A hint that it's not a real save point is that it's blocking the way, which the genuine ones never do.
• The Unintelligible: The Reaper Bird begins speaking with multiple dialogues overlapping over each other. It eventually separates into the individual components if you comfort them. The Memoryheads can also speak in a horrible distorted screech that resembles a dial-up modem, but comes in fine through the cell phone.
• Voice of the Legion:
  • Lemon Bread's dialogue consists of twelve different speech bubbles covering the screen with the same dialogue.
  • Reaper Bird speaks three different speech bubbles at once, layered over themselves, and they separate when close to sparing.
• Voluntary Shapeshifting: They disguise themselves in a variety of ways, such as being water in a sink (Memoryheads), a refrigerator (Snowdrake's Mother), floating particles (Endogeny), a save point (Lemon Bread), and even your "!" balloon (Reaper Bird). Save for Endogeny, the forms they take in their overworld sprites are also nothing like the ones they use in-battle.
• Was Once a Man: All of them used to be multiple monsters. Monster bodies don't have the same physicality as human bodies, so their transplanted Determination caused their bodies to melt and fuse together instead of simply allowing their souls to persist after death.
• Weaksauce Weakness: Endogeny is a dog, so the Stick will instantly pacify it as it does with all other dogs. If you already used your Stick, then the Hush Puppy you can get at the hotel has the same effect.
• What Happened to the Mouse?: The Memoryheads and Reaper Bird completely disappear from the story after you deal with them in the True Lab. This is because neither of them are shown to have any family in the Underground, unlike the other three Amalgamates.
• You Cannot Grasp the True Form: Definitely gives off these vibes, especially since their battle music takes a sample from the Trope Namer. For example, before reaching Spare conditions, Reaper Bird's name is given as a single comma, and the Memoryheads are completely incomprehensible unless communicated to through your cell phone.
• Zero-Effort Boss: Snowdrake's Mother tries to attack, but she's so messed up that she can only fire slow projectiles that deal low damage and usually don't make it anywhere near the SOUL. Sometimes, they don't even make it to the Bullet Board. She's also one of the easier Amalgamates to Spare, with the player only needing to tell her a joke three times.

The Anomaly

The Anomaly

"It's literally you."

Thought you were just the Player Character here? Nope! Frisk and the player are implied to be separate entities in Undertale; the latter simply dictates the actions of the former. But remember that Undertale isn't a typical RPG; all of your choices will affect the game world... for better or for worse.

Depending on the interpretation, you either play as the Fallen Child (see their page) or yourself. Either way, this page describes the role of the Anomaly.

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• Above Good and Evil: Since the world of Undertale is fictional and you're not, you are essentially this. However, the game will attempt to tell you that you aren't, especially in the No Mercy route.
• Abstract Apotheosis: As noted in Sentient Cosmic Force, you're a being only visible in consequences that happen in the timelines, you are the driving force in the world, it's your choices and determination that replaces Frisk's. Thus (if perhaps only in the "purity of action" sense of the trope or perhaps something more literal), you are not just a Determinator, you are DETERMINATION itself.
• Achievements in Ignorance: Simply by starting a fresh new game, you essentially take away Flowey/Chara's ability to SAVE and LOAD.
• All for Nothing: If you wait long enough in a post-Genocide Run game until Chara/The Fallen offers you to get a second chance in exchange for your soul. Accept the deal, and you can try to get a Pacifist Run properly... until the last scene, in which Chara/The Fallen will take control away from you and kill everyone themselves, rendering all your effort moot.
• All-Loving Hero: It's very easy for a pacifist player to take this route.
• Ambiguously Evil: One of the game's primary artistic purposes is opening up questions about human morality regarding how they treat circumstances where actions have supposedly no consequences. Stereotypes aside, odds are you're not actually an evil person; you just wanted to see what would happen if you killed everybody or only killed certain people. The question here is whether or not these actions actually have any true moral significance — not to the point where it's worthy of real-life reprimanding, obviously, but still enough to make the player introspect and question themself and their actions.
• Ambition Is Evil: Maybe. The Anomaly's morality is called into question by Sans, but one of the theories he proposes is that you're doing the Genocide Run in order to satiate your constant need for stimulation.
• The Antichrist: In the Genocide run. You fit the archetype regardless if you're playing as Chara or not. A figure of unending destruction who helps bring about The End of the World as We Know It.
• At Least I Admit It: Post-Genocide, should you try to play the game again, Chara will claim that you actually believe you're above consequences. There's nothing stopping you from outright admitting that's the case, and indeed, the only way to keep playing without permanently tainting the Golden Ending is to modify the save files in order to subvert the very consequences the game had in place for you.
• As Long as There Is Evil: The fact that you exist and can reset the game at any time — erasing all the progress and memories made — theoretically makes you the single most potentially evil — and unstoppable — entity in the story.
• Ax-Crazy: In the genocide run and the darker neutral runs, you are one of the biggest examples in videogame history; after all, name one character who tediously hunts down an entire country and kills them one by one, and if you choose to erase, destroys the entire gameworld. Emphasis more on the ax than the crazy, as in real life you're likely much more sane and kind, hopefully.
• Benevolent Abomination: You are this by default, especially in the Pacifist run. Sure, you are still an Eldritch Abomination that exists beyond the realm of the monsters and can warp their very lives without any of them knowing, but this time, you are doing so for their benefit. Trying to find a way to give everyone the best lives they can live while simultaneously trying to release them from the underground.
• Beyond Redemption: Did you go through an entire Genocide route and think that you can make things right again by doing another Pacifist run? Sorry, the game remembers that you did the deal with Chara and they will remind you of that once you finish that run as well.
• Big Bad: During a Genocide run. If you are playing as yourself and not the Fallen Child, they will take control by the end of the Genocide route, forming a Big Bad Duumvirate with you, though only for the Fallen to pull an Eviler than Thou.
• Big Bad Wannabe: You become this if you complete a Genocide Run. Across the entire run, you basically walk around, forcing Frisk to kill everything that walks until you find your way to Asgore and one shot him. Who awaits you at the end of this long journey? The Fallen Child, who wastes no time putting you in your place and letting you realize just how wide the gap between them and you really is.
• Big Good: In the Pacifist route, you help everyone solve their personal problems and reach the surface.
• Blood Knight: Many a player has been convinced to do a Genocide run for the sole purpose of doing battle with Undyne the Undying and Sans, seeking a new, harder challenge.
• Blue-and-Orange Morality: There's a creature in the game's canon that exists outside the universe. This creature can't manifest into the world by itself, but it can take control of a host and puppet them around. Whether it befriends everyone or commits systematic genocide, this creature does it just to see what will happen. It remembers everything that's been done to it, in all timelines, even when their host body has been destroyed numerous times. What is this creature? It's you.
• Combat Sadomasochist: On Genocide route, Sans will accuse you of being this if you defeat him, reload, then fight and defeat him again, then reload and fight him again. Considering you went through hell and did it one more time just to see his reaction…
  "... you're really kind of a freak, huh?"
• The Corrupter:
  • Frisk's LV (or/and the The Fallen's LV) is a measure of their Killing Intent, and the player is technically responsible if it's above the lowest level.
  • If you believe you're playing as the Fallen, you can exploit Frisk's determination to increase your own power, eventually getting them to sell their soul so you can use them to destroy timeline after timeline.
  • If you believe you're playing as yourself, you corrupt the Fallen by using Frisk to kill others. Eventually, they become corrupt enough to take control of Frisk from you completely, even in future playthroughs.
• Cosmic Chess Game: You're a player for once instead of a pawn; your opponent is Flowey, the only other character to use determination and who flat-out calls it a game, and also possibly Chara, though they will normally remain submissive to you.
• Cosmic Horror Story: You can easily turn the entire game into this if you so choose. There is no character within the game, not even Flowey or the Fallen Child, who can match the sheer cruelty you can inflict upon the world. Arguably, the game is this merely by virtue of the player's relationship to it, regardless of how they actually use their power.
• Cosmic Plaything: You become this if you sell your soul to Chara. You're allowed to start over, do Pacifist, Neutral, or Genocide… all under the fallen human's constant supervision. Though you can, of course, completely avert this at your own discretion if you decide to modify the saving files.
• Curiosity Is a Crapshoot: On the Genocide route, Sans will acknowledge that you probably aren't murdering everybody because you're a sadist — you just want to see what would happen, and as far you would be able to tell at that point, you could easily reverse it any time you want. The problem is that, by completing the Genocide route, you can't reverse it and will doom everyone in the game forever.
• The Dark Side: You can be the Dark Side, feeding Chara power and corrupting them into evil and being the Antichrist to your Satanic Archetype at the same time. (Only in the genocide run or when you kill somebody, really.)
• Determinator: You have to be to get one of the true endings, or even make it to the end after all the deaths you'll get; determination and the resolve to achieve what you want is one of the game's main themes, and it's heavily encouraged in players to match Frisk and the Fallen Child.
• Detrimental Determination: The gist of the Genocide Run, especially after a True Pacifist Route. You become so determined to see everything the game has to offer, that you go from forming deep bonds with the many monster living underground to butchering them in cold blood, becoming absolutely hated and feared for it as a result, until you reach the end where Chara/The Fallen decides to destroy the world to demonstrate the difference in your power.
• Dragon-in-Chief: Depending on how you see Chara and their relationship with you, either you are this to them or they are this to you, or you're on equal terms.
  • It's the Fallen Child's LOVE and stats Frisk (and you) are using.
  • It's you who actually does all the work, dodges the attacks, etc., with Chara simply providing the muscle and information.
• Dragon with an Agenda: Whether you're the dragon to their Flowey or Chara/The Fallen, it's more than likely you'll have your own reasons for following along the Genocide Run, whether it's to satiate your own boredom or something else.
• Dramatically Missing the Point: Plenty of players have gloated about how they've outsmarted Chara by, after completing a Genocide Run, editing the game files in order to give themselves their Golden Ending back, thus proving that they don't "think" they are above consequences, they are above consequences… all while completely overlooking the fact that them doing this proves that they acted in exactly the way Chara has predicted them to: refusing to accept any kind of lasting negative consequences for what their own actions did to the game. In fact, answering Chara's accusation that you believe you're above consequences with a Blunt "Yes" simply has them agreeing with you.
• The Dreaded: It's perfectly possible to be this even though everyone will think you're Frisk, but well, basically the entire underground will fear you.
• Eldritch Abomination: A being beyond comprehension, the same species as the creator of the world, utterly beyond punishment and capable of altering reality with ease. Powers include possessing Frisk, returning lost beings back into existence, resetting the world, and, yes, even undoing what cannot be undone. Sans can only speculate why such a being would do what it does.
• Empowered Badass Normal: A normal human, armed solely with your determination and your skills as a player and possibly a hacker, given a computer, an Undertale program, and Time Master and Demonic Possession powers over Frisk and the game world. That's all you need to fight and defeat/conquer even the greatest opponents and challenges the game has to offer, such as Sans and Undyne the Undying.
• Eviler than Thou: When it comes to Flowey and Chara in a Genocide route:
  • By the end of the route, both you and Chara turn on Flowey and by the end chop him to pieces. A short conversation later, Chara pulls this trope on you.
  • Invoking this is about the only way you can get a semblance of victory over the Fallen Child, baffling them with your sheer depravity.
  • Have you done a Genocide Run but don't want to sell your SOUL? Don't even bother to open the game again after Chara crashes it. Just straight up uninstall it right then and there (and if you ever want to play it again, you may reinstall it). If you do that, you can pull this trope on them.
• Evil Is Not a Toy:
  • The fallen human will tell you this and punish you for your misdeeds at the end of a Genocide route.
  • You can invert the above example by simply uninstalling the game after Chara crashes it without going back to listen and take their deal.
  • Invoked at the end of the Pacifist Route, when Flowey reminds you of the responsibility you have of guarding the reset button.
• Expendable Alternate Universe: Want to keep playing the game, even after getting the Golden Ending, and Flowey asks you nicely not to? Just copy your save files! Everyone gets to keep their happy ending, while you still get to have fun…
• Face–Heel Turn: Any player who gets the True Pacifist ending, then resets and starts a Genocide run pulls one. For a while, you still have a chance to turn back.^note It is usually considered that beating Sans and resetting is not too late, but entering the throne room and initiating the ending is. From a technical standpoint, you're safe as long as you don't make the game's final choice. It should be noted, however, that by that point, you've lost the ability to QUIT. The only way to reset once you're that far is to forcibly shut the game off.
• Fighting a Shadow: The main reason why no one can hurt you, no matter how badly they want to. You're in Real Life, a literal higher plane of existence, using Frisk as your avatar in the game world; how are they supposed to reach you, much less do you harm?
• From Nobody to Nightmare: If you choose to take the No Mercy run, you go from attacking common monsters to mutilating bosses in one hit to destroying the world with help from the fallen human.
• Gaining the Will to Kill: Depends on the player, but given how much of a grind the actual Genocide Run can become, you'll need to develop at least some Killing Intent in order to move forward. This is especially true should it come after a True Reset, as you'll have to go from forming bonds with the many denizens of the Underground you've come to grow attached to, to killing them without remorse as you become more and more powerful, and distant, as a result.
• A God Am I: Invoked. Flowey will call you out on your attempts to shape destiny.
• Good Is Not Soft: While it is encouraged to be spare as many monsters as you can, however, there is nothing from stopping you from beating up the ones that want or deserve to be beaten up, and you can then spare them once their HP is low enough.
• Greater-Scope Paragon: In a meta sense. Since Frisk is the main character and Sans and Toriel are both technically the Big Good, that technically makes you the greater scope paragon of the entire game, since you're technically responsible for most of what Frisk does in the story… assuming that you aren't going for a genocide run, of course. That being said, on the flipside…
• Greater-Scope Villain: ...Also in a meta sense. With the Narrator Chara theory gaining more and more supporters, the Undertale fandom in general has come to the consensus that it's not Chara's fault — it's yours for making Frisk do the genocide route and causing the world's destruction. These days, you'll find much more YouTube comments along the lines of "Chara is evil in a Genocide Run, but so are you and/or you made Chara that way!" than the latter. Heck, there's even a YouTube video out there with the song "When You're Evil" regarding the player, not Chara. Given that there's no Word of God on the issue currently though, it's all open to interpretation, much like many other aspects of Undertale. This trope only applies if you're going for a No Mercy/Genocide run.
• The Hedonist: Sans in a No Mercy run accuses the Anomaly of never being happy, always wanting more.
• Heel–Face Door-Slam: Interestingly enough, this only ever happens to you, the player, in the aftermath of a Genocide playthrough. Once you've done this, and sold your soul to recreate the world, you will never have a true Golden Ending again without cheating. For everyone else, though, this trope is averted and characters who have done terrible things will be forgiven, since, well, that's what the game is about. Alphys, who's responsible for innocent monsters being turned into the molten-together and horribly disfigured Amalgamates, gets fired from her job when she tells the truth, but since monsterkind is about to leave the underground anyway, this won't actually be a bother — and her friends continue to be by her side anyway. Asgore, who has the blood of six human children on his hands, is still a respected leader. And in most cases, you're the one to show mercy, like with Undyne or Flowey.
• Heel–Face Revolving Door: A player who goes through several runs choosing a different route each time is essentially this.
• Heel–Face Turn:
  • The game allows a player on the Genocide path to step off it up until the Mettaton NEO fight. When Papyrus, for example, offers to Spare you, it's a genuine offer with no strings attached, and will revert your game to a Neutral one. Sans' offering, on the other hand, is not.
    • It's possible for the trope to still be played straight after the player accepts Sans' false offer of mercy, if the player takes the skeleton's words to heart and RESETS after getting dunked on. Of course, this depends entirely on you.
• He Who Fights Monsters: It's pointed out by Sans that the more you kill, the more emotionally distant you grow, in an It Gets Easier manner. Considering that all monsters display Fantastic Racism with a few rare exceptions and most of them are actively try to kill you, it's not too weird to start killing in self defense and then just keep doing it.
• Hijacking Cthulhu: From the moment you start Undertale, you've unwittingly seized the power to SAVE and RESET away from Flowey/Asriel, and he really doesn't take kindly to this.
• Horrifying the Horror: If you finish at least two No Mercy runs, even Chara won't be able to understand your actions.
• Humans Are Cthulhu: Everything in the game world is up for your own amusement. There's absolutely nothing the entities within can do to harm you. Even when Chara pulls an Eviler than Thou to screw you over beyond the fourth wall after a No Mercy run, you can screw them over beyond even that by actively editing the game's codes. "But TVTropes," you say, "surely that's out of universe, not a real part of the actual game!" …Except the intentional Easter Eggs accessible by altering the game's files suggest that it is a valid mechanic. Sufficiently informed, you can manipulate anything in the game.
• Humans Are the Real Monsters: Should you decide to go full Genocide or kill almost everyone in a more neutral route.
• Humanoid Abomination: In Undertale, the line between Chara, Frisk, and the player gets extremely blurry, so their "inhuman" descriptions in the Genocide Route should probably be taken to include you. If that is not eldritch enough, see the Eldritch Abomination entry, so yeah, you fit straight here, especially in No Mercy; has it occurred to you that maybe, just maybe, Chara is able to take your (or Frisk's) SOUL despite humans not being able to hold the souls of other humans, because you're no longer human and not Chara?
• Incorruptible Pure Pureness: The player who chooses to go full pacifist, ensuring the happiest of endings, and never play the game ever again (or watch anyone else play the worst endings), achieves this trope.
• Invincible Hero: If you're truly Determined to give as many characters as possible their happy ending, or to slaughter the entire Underground, then there's nothing anyone can do to stop you; Flowey will become just a minor irritation, as will all your possible deaths. In a greater sense, you yourself are literally invincible, as you exist in a different dimension than the characters.
• Invincible Villain: There is also nothing the characters can do to stop you from doing a Genocide run, aside from trying to talk you out of it or hoping you'll get bored and give up. With your Determination, every defeat is just a setback. Even the Fallen Child after you've sold your soul to them can be beaten by editing the games files.
• It Amused Me: During the final battle of the Genocide route, Sans will start speculating on your motivation for all the evil things you've committed. At first he considers that you might simply enjoy killing things, but then brushes the idea off as ridiculous, saying that "you're the kind of person who won't EVER be happy". He then goes on to accuse of you of this trope, saying that you're not even motivated by good or evil anymore, you're just doing this because you can. And because you have that ability, and are seemingly above consequences because of your ability to SAVE, you just can't help yourself. It's a gamer's natural desire to seek out and accomplish everything in a game, after all.
• I Want My Beloved to Be Happy: If you listen to Flowey and choose to abstain from a True Reset after getting the Golden Ending, letting the characters you've grown to know and love happily live out the rest of their lives without you. Believe it or not, quite a few fans will admit to having done this.
• Karma Houdini: No matter what bad thing you will do, the in-game characters will be the ones punished. Nothing bad happens to you. Not even the Omega Ending is a lasting punishment since you can just erase all save files from the game and start over with a fresh file.
• Karma Houdini Warranty: Double Subversion. If you reach the end of the Genocide Run, you'll have essentially used Frisk to wipe out the entirety of the Underground, only to meet The Fallen/Chara, who proceeds to kill you alongside the entire world with one swing. If you wait long enough in the post-Genocide Run game window, Chara will give you a choice to start anew in exchange for your soul, which seems like a subversion at first. Get to the end of the True Pacifist route here, however, and Chara/The Fallen will take control of Frisk and kill everyone anyway, ensuring you can't get the happy ending you worked so hard to get. Triple subverted if you manage to erase the game's save files and start fresh.
• Knight of Cerebus: In any kind of run that's not Pacifist (a.k.a. did not kill everyone). Not only is there a good chance you have a huge body count behind you, but the Underground changes hands, and always for the worse — it can devolve from tyranny to anarchy to becoming an Egopolis and everything in-between. And you are the one who started it. And that's not even getting to the Genocide/No Mercy run, where you basically destroy reality.
• Lack of Empathy: While you aren't forced to sympathize with the cast even in the Pacifist route, not getting attached to the characters is pretty much a requirement in the Genocide route as you have to kill all of them, oftenly in horrible ways, while most of them are standing before you as paragons of virtue.
• Lovecraft Lite: Despite all those horrifying things that you can do in the game to this world and its people, nothing can make you do them. It's possible to achieve the Golden Ending without killing anyone… and even if you want to replay the game, you can always abstain from the No Mercy route and achieve the Golden Ending again.
• Mistaken Identity:
  • If you believe you are playing as yourself and not the Fallen Child, then any time Flowey addresses you as the Fallen will count as this.
  • A subtle example in Sans. He seems to be the only character (aside from possibly the Fallen) who confirmably knows that you even exist — but while he correctly identifies you on a Genocide run as the cause of the latest resets, he doesn't seem to realize that you haven't always been the one resetting the timeline. Flowey's speech a few rooms earlier gives the impression that his reign as resetter was a Time Abyss; most likely, he was responsible for far more loops than the player ever could be. Sans never seems to realize this. However, it's not clear whether the "anomaly" in question is Frisk or the player since it's unclear who's truly in control of all resets.
• My God, What Have I Done?: The game tries very, very hard to evoke this feeling out of you the entire time you play the Genocide route, and during worse Neutral endings, in the hopes you'll Reset.
• No Challenge Equals No Satisfaction: It's the aspect about you that Sans fears most. You're neither doing anything good because it's the right thing to do, nor anything evil for sick pleasure — but simply because it's a challenge. And because you can achieve it, you may feel required to.
• No Kill like Overkill: Your damage becomes ridiculously excessive in the Genocide route.
• Nominal Hero: You don't actually have to feel sympathy for the inhabitants of the underground, but can still go through with the Pacifist ending because you find it to be an obligation. (Which it is, if you want the final ending.)
• Nominal Villain: Similar to the above trope, you don't have to be genuinely malicious while going through a Genocide route, but still go through one because you find it an obligation to see everything the game has to offer.
• Omnicidal Maniac: In a Genocide run, the Anomaly decides to kill every single living creature it can, despite the fact that none of its victims can even begin to hurt the Anomaly.
• Omniscient Morality License: Since you have the ability to go back and fix things whenever you want, just like any other video game, you essentially have omniscient control over the game's universe and may be tempted to succumb to this. If you do, you'll be faced with quite a bit of harsh deconstruction.
  Sans: sometimes... you act like you know what's gonna happen. like you've already experienced it all before. this is an odd thing to say, but... if you have some sort of special power... isn't it your responsibility to do the right thing?
  No
  Sans: heh. well, that's your viewpoint. i won't judge you for it. ... Y o u d i r t y b r o t h e r k i l l e r.
  • Also, going all the way with a Genocide run punishes you with a Heel–Face Door-Slam.
• Outside-Context Problem:
  • You're a being from outside the universe that none of the characters could have ever predicted would have shown up and whose nature is inherently different from all of them. They can do nothing to stop you no matter what you do, as you operate on completely different rules than they do. In a temporal sense, you simply shouldn't exist. How can you when Flowey has already reset the timeline repeatedly and you were never there before? You are, as Sans dubs you, a literally inexplicable anomaly in time.
  • Your ability to SAVE and RESET are extremely rare abilities in the game's setting, but certain characters can use them. Your ability to alter the game's data, however, is something none of them could ever replicate.
• Pay Evil unto Evil: You can take the game's story and characters 100% seriously and still choose to kill some of the more aggressive monsters if you think they deserve it.
• The Perfectionist: If you're trying to do a specific playthrough, yet reset or save scum after every screw-up. Flowey may even call you out on it depending on the circumstances.
• Person of Mass Destruction: As Sans describes it, a Genocide path will not bring you any kind of satisfaction, you'll just keep consuming timeline after timeline.
• Player and Protagonist Integration: You start controlling Frisk as a Heroic Mime, and in most playthroughs, that is all that you are. By the end of each route, it's implied you're separate entities: either you are playing as the Fallen controlling Frisk, or as yourself.
• Pure Is Not Good: You will need a single-minded determination if you want to get the Golden Ending or to complete the Genocide Run. Sans says this evil purity is the most dangerous part of you.
• Redemption Equals Death: If you take Sans up on his offer of friendship at the end of the No Mercy run, he'll kill you and tell you that if you were sincere about being friends, you'll never come back. Though this is an interesting twist on the trope because Sans is well aware that you're unkillable you can't be Killed Off for Real because you can control time, so his saying that doesn't mean "stay dead", he's telling you "reset and be a better person".
• Satanic Archetype: Genocide Anomaly is the best example. A pure evil Eldritch Abomination (the same species as The Maker) who rebels against the creator of the game's desire to free monsterkind out of Pride and your own selfishness, abandoning all notions of goodness and consigning yourself to the most evil route by becoming the Angel of Death (which is one of Satan's many monikers) and creating an Antichrist (who you serve as The Corrupter to) to serve as your Earthly envoy and agent of destruction. Players who did a Pacifist Run first also fit the Fallen Angel and Fallen Hero tropes, and even invoke a bit of Demonic Possession during their control of Frisk. Out of all the characters, you are the closest thing to Satan.
• Screw the Rules, I Have Supernatural Powers!: You have the power to SAVE, and reset, time itself, if you so choose. However, you're not the only character who can handle that raw kind of power; Asriel and Chara will try to wrestle it back from you, and with the latter it's for keeps. Though the fact that you can go a step beyond and edit the files of the game means that your powers will (in a meta sense, anyway) always outclass Chara's.
• Sentient Cosmic Force: An interpretation, as you're a being only visible in consequences that happen in the timeline; you are the driving force in the world. It could be said that you are Frisk/Chara's DETERMINATION.
• Set Right What Once Went Wrong: Should you ever have a change of heart during the Genocide route, undoing your mistakes via a Reset is always an option. Once the route has been brought to completion and the entire world has been erased, however, you'll have no choice but to live with your wrongdoing. A complete inverse of this is the player who decides to do a Genocide run after fulfilling True Pacifist.
• Superpowered Evil Side: For Frisk, especially when you start killing literally everyone against Frisk's will; remember, Frisk is just a little kid who most likely would not want to hunt down and kill every single monster, and even if they did, being just a child they probably wouldn't have been able even if they tried. You're the one fighting, the one dodging, and the one killing. In pacifist, you're a much more benevolent Super-Powered Alter Ego. In a very confusing double whammy, should you interpret Chara's speech as literal, Chara by the Genocide ending could be interpreted to be yours, an embodiment of everything destructive you've ever done in videogames given life by your own hands.
• Space Time Eater: A sentient time-space anomaly that can consume as many timelines as it wants.
• Spanner in the Works: The player character can be this, most obviously in a Pacifist Run. Regardless of the run, you undermine each boss' plans to either keep you as a guest or prisoner, kill you, and take your soul to the king or for selfish purposes, or stop you from destroying the world. In fact, once you become friends with everyone, you then undermine Asriel's plan to remake the world and start afresh because you remember each of your friends' likes and dislikes while they are trapped inside Asriel.
• Stupid Evil: Although there are some interesting things to be found within, like character development, very few people consider the Genocide Route even remotely as enjoyable as the Pacifist route, for a myriad of reasons. It's significantly harder, for example, to the point where the final boss is very clearly designed to be as unfairly frustrating as possible, and the humor and charm is all but nonexistent. As such, many would consider it an unnecessarily exhausting, unsatisfying, and emotionally draining journey to partake in, and Sans, the only character who's aware of your existence, clearly agrees. When analyzing you psychologically at the end of his boss fight, he comes to the conclusion that the only reason you're still here is because you can be.
  Sans: and because you "can"... ...you "have to".
• Symbiotic Possession: The player controls most of Frisk's actions, but a more benevolent player acts closely to Frisk's desires anyway. As Frisk is a child, they arguably couldn't complete their quest without you, even if they could use determination on their own.
• Time Master: In this game, resetting and reloading are real, in-universe things, which you gain complete control of just by starting a new game.
• Talk to the Fist: On the Genocide path, you often walk up to the major characters and one-hit-kill them without a word.
• Technical Pacifist: Possible if your main method of Sparing is to beat the opponent until they have low health, though the fact that monsters take more damage the lower their health is makes this impractical. You can also engage in multiple Kick the Dog moments via dialogue options without having any impact on a True Pacifist run.
• Tom the Dark Lord: You are most likely going to be this in a Genocide run. Why would your own name be scary?
• Troll: You can very much be one by all means as you can choose to screw around with the monsters you encounter. This is best demonstrated by how you can make the Training Dummy Rage Quit by doing nothing useful for eight turns.
• The Unfettered: Undertale is heavy on meta commentary about how your actions can affect the game's world for the worse, what might be your reasons for pursuing bad outcomes, and even how much you're willing to cheat to take what you want from the game. If the worst comes to pass, Sans accuses you of having done it all just because you could and the Fallen Child outright calls you the sort of person who thinks themself to be above consequences and who acts on perverted feelings for the game's setting. You can prove that and assert your power over the game by erasing the records of your deal with the fallen human. On the other hand, there are plenty of people out there who have resisted the temptation of doing a Genocide run and who even hesitate in doing a True Reset after listening to Flowey's last request. However, the game does not spare calling out those who may have been pacifists themselves, but watched someone else take the Genocide route instead.
• Virtual-Reality Warper: You can delete and edit the game's files, which clearly makes you this in a meta way, and, as said everywhere else, Undertale is a very meta game on purpose — then there's the ability to reset…
• Vile Villain, Saccharine Show: One of three, along with Flowey and the Fallen Child, as you are the one who plays the No Mercy run, which makes you the biggest Knight of Cerebus; interestingly, you have the choice to be the reverse and make the game happy and quirky.
• Villainous BSoD: A very, very common reaction — the intended reaction, even — for those who play the Genocide route, especially those who had no idea what they were getting into. This best demonstrated when willing either Toriel or Papyrus, or when Monster Kid decides to engage an encounter to stop you in your tracks. Some choose to reset and undo their mistakes at that point, while others choose to grit their teeth and press on anyway.
• Well-Intentioned Extremist: You can invoke this (especially if this isn't your first playthrough) as an excuse to kill every boss monster while sparing the citizens. This results in the Annoying Dog taking over the throne, and arguably the second-best ending in the game right after True Pacifist. Even Sans would say thanks at the end of it, despite him being rightfully angry at you for killing his brother earlier. This can also apply to players who started out sparing the monsters but killed at least a few of the later encounters because they just couldn't find out how or they didn't find them to be worth the effort.
• What the Hell, Hero?: Beating the game on the True Pacifist Run and rebooting the game gets you a lecture from Flowey of all characters, calling you out on taking the characters' happy ending away from them because you were bored, and referring to you as a possibly worse person than him.
• Wrong Context Magic: Even if it's only a few people, there are those who know about the power of determination and resetting. What they don't know about is the Anomaly's power to alter the game's data. Even Chara's attempts to trap them with the consequences of the Genocide run are nothing in the face of this.
• Wrong Genre Savvy:
  • The first boss asks you to prove that you're strong enough to survive outside. Anyone familiar with Role-Playing Games in general^note particularly Mons-catching games such as Pokémon would try to beat Toriel to an inch of her life before Sparing her. The encounter's designed so that she's instantly killed when her health reaches 30%, and you're guaranteed to feel like a scumbag afterwards.
    • Interestingly, on a Full Pacifist Route, the game does this to you again with Asgore, but in reverse. Asgore's boss fight plays the RPG trope straight, you have to fight and beat him within an inch of his life to Spare him, but by then you've played almost the entire length of the game having adapted to its new rules. You end up frustrating yourself trying to find a hidden (non-existent) trigger for a non-violent Mercy Condition just as you've done all game for every other monster. Wrong Wrong Genre Savvy?
  • The game itself is very meta, and if you think you can just save and load as you please to see what would happen if you do this or that, you will be in for a nasty surprise.
• Yandere: You can be a platonic version of this if you reset a True Pacifist ending, taking away a happy ending in order to spend more time with characters you've grown to love.
• Yank the Dog's Chain: How the aforementioned permanent Heel–Face Door-Slam manifests. Even if you do everything right and get a Pacifist Ending, in the end, the Fallen Child is revealed to still have your soul, after which they'll take control and possibly starting killing again, anyway.
• Your Approval Fills Me with Shame: Just like My God, What Have I Done? trope above, the game evokes this trope to the player at its hardest. When Flowey or Chara/the fallen human congratulates you, the player (and/or Frisk) for killing Asgore and/or Flowey himself in the Neutral route on the former, and completing the Genocide/No Mercy route on the latter.

Dr. W. D. Gaster

Dr. W. D. Gaster

The "Mysteryman" sprite commonly believed to be Gaster.

"THIS NEXT EXPERIMENT SEEMS VERY VERY INTERESTING."

The enigmatic Dr. W. D. Gaster was the original Royal Scientist, before Dr. Alphys. Can't find him? Well, that's no surprise—he's barely in the game.

Originally, if one were to explore the game's files, they'd come across a few odd NPCs, rooms, and messages that appeared to be cut content. After the Internet took note of them, they were changed to extremely rare Random Events instead.

Either way, what follows is the mysterious tale of a brilliant mind who fell into a creation of his that accidentally caused him to be shattered across reality, with his fate uncertain. Even to this day, no one knows the complete story of W. D. Gaster... well, no one that wants to talk, anyway.

A second Goner was also added in the Switch port, and a figure implied to be very close to him (if not him) facilitated the reveal of Undertale's successor, Deltarune, with the game itself having a notable amount of nods to the mysterious scientist. As for what this means, however…

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• The Ace: The former Royal Scientist, a highly esteemed position, who was well-regarded in his field and hailed for the creation of the CORE that powers the world of the monsters. His followers can only wonder if Alphys can measure up to his talent.
• Ambiguously Evil: Gaster is certainly an ominous figure, but he doesn't actually do anything to suggest he's malicious. Due to just how unknown he is, its really impossible to discern his true nature or what, if any, plans he might have. He might be a bad guy, he might not. Then again...
  River Person: Beware of the man who speaks in hands.
• Ambiguously Related:
  • To the mysterious voice who unveiled Deltarune to the internet. While their manners of speech are near-identical, and the voice pointedly states that it thought we would find Deltarune "VERY, VERY INTERESTING," no official statement has been made.
  • To Sans, thanks to his weapons being known as Gasterblasters in the game files (this being one of the few places Gaster's name shows up at all), as well as his scientific interests. This extends to Papyrus by proxy.
• Ambiguous Situation:
  • Gaster's life was cut short, and he fell into his creation. But the followers don't make clear if it was an accidental death because his experiment went wrong, or one on purpose after his experiment went wrong. One of the followers wonder if Alphys will end up the same way, which may be about her suicide in multiple neutral endings. This isn't even bringing up the possibility he was pushed into his creation.
  • It's also not specified which "creation" he fell into. The most likely candidate is probably the CORE, since it's his only confirmed invention — but it's also unclear how a geothermal-powered magical electricity engine causes one to be "scattered through time and space", unless there is some detail about its operation we don't know about. Other candidates for his creation include the Determination Extraction Machine (found in Alphys' True Lab, but it's implied that she might have not been the one to design it) and the mysterious machine in Sans' secret room.
  • It is unclear whether Gaster's fate should be taken as him being completely Ret-Gone, or just being forgotten about in the mundane sense. In particular, Goner Kid asks about a world where everything is exactly the same except you don't exist, which could be taken as Gaster's fate, but the Gaster Followers describe him as a Tough Act to Follow with a large gap between him and Alphys, implying some memory of his greatness lingered on. Related is the interpretation that Gaster is an In-Universe exploration of a Dummied Out character.
  • The Riverperson's warning to "beware the man who speaks in hands" is almost universally believed to refer to Gaster, but it's not as clear-cut as the fandom would have you believe, considering that this would make the Riverperson the only character to talk about Gaster besides his followers, and not every symbol used by Gaster is a hand. Another of the Riverperson's warnings, "beware the man who came from the other world", is similarly questionable; it could refer to Gaster since he doesn't reside in the world of Undertale, but he also isn't really from another world as far as we know, he's just not in this one ^note  unless you count the timeline from when he existed as "another world". Unlike the former quote, there are alternative candidates for this, mainly Sans, So Sorry, or Chara.
• And I Must Scream: Implied. Goner Kid talks about horrible it is that the world moves on without you but still looks exactly the same, as if you never mattered. And since the goners are implied to be connected to Gaster in some fashion, it's not too much of a stretch to assume that Gaster is suffering from his "scattered across time and space" situation.
• Beyond the Impossible: His report mentions negative photon readings, which is a physical impossibility.
• Body Horror: One of the NPCs who speaks of him claims to be holding a piece of him, and his Mysteryman fragment has two gashes on his face - one blinding his left eye, the other cutting into his mouth.
• Caps Lock: Gaster's Entry Number Seventeen is spoken in full uppercase Wingdings, and that font only has the hand symbols he's seemingly associated with in uppercase. Interestingly, there is a second hidden character in the game that speaks in Wingdings with the same Voice Grunting as Gaster but does not use full uppercase and only spouts lines like "redacted".
• Cryptic Conversation: Everything related to Gaster in Undertale is this, from his report about an expanding darkness directed at two unknown people to several entities displaced in time-space gossiping about him and a voice asking players for "feedback" on his theme song before leaving.
• Dem Bones: The font Theme Naming convention he shares with Sans and Papyrus, as well as the appearance of the Mysteryman, heavily suggest that he is/was a skeleton monster.
• Do Not Taunt Cthulhu: Implied. Trying to enter "Gaster" as the Fallen Child's name causes the game to boot back to the title screen. Many of the Gaster followers are extremely hesitant in divulging information about him, only giving the player bits and pieces of his backstory at a time before shutting themselves up. However, when one of the Gaster followers arrogantly talks more than he should, he gets erased on the spot.
• The Dreaded: Along with his status as a once powerful scientist, he has many associations with the number 6, meta game mechanics, Determination, and general warnings to be wary of or avoid even speaking of him. Whoever Gaster was, it's possible he was, or is now, very dangerous. "Beware of the man who speaks in hands."
• invokedDummied Out: Originally, all evidence of Gaster's existence was locked away in the game's files, unable to be accessed normally; players originally learned about him by fixing a "typo" in the game's save file (changing the "fun" item to "Fun" and setting it to certain values). After a patch, the "typo" was corrected so the Fun value worked properly, allowing much of the Gaster-related content to be accessed legitimately (albeit under very unlikely circumstances), including the Gaster Followers, the Goners, and the Mysteryman encounter. Some of it is still only found in the files however.
  • His Entry Number Seventeen report (Room 264, room_gaster) is completely inaccessible outside of hacking the game, as he details his "next experiment" to two unknown individuals.
  • room_water_redacted, or Room 272, is a blank, empty room with a mysterious figure in the middle of it. Regardless of whether the character itself has ties to Gaster (it only says a single word in Wingdings, being "[REDACTED]"), the room's exit leads to the Sound Test, the one place in the game where you can listen to Gaster's Theme. The room is implied to have originally been accessed by a cut stable placed in Waterfall near where the snail race takes place, where it was locked. The stable could be unlocked by locating a hidden key in a trashcan, after which the mysterious figure in Room 272 would show itself inside of the stable when the player got near. An additional piece of code implies that the key could then be used to open the stable, presumably leading to Room 272. After this sequence was scrapped, it seems it was given a Gaster-themed coat of paint for dataminers and then removed. It's possible this may have originally been Grandpa Semi, due to code in the demo for Undertale saying he was meant to be found in Waterfall, although this could also have simply been an early incarnation of the Mysteryman encounter.
  • There is also an actual cut character known as Grandpa Semi. The name was found in the Undertale demo's code, and he was likely going to be the one to call Frisk for pizza in Snowdin (in the final game, Alphys does this), while an audio file bearing his name quotes the opening of "Metal Crusher". (See here.) That's all we know about him, but since "Semi" could refer to semi-serif fonts, many think Grandpa Semi is a proto-Gaster.
• Eldritch Abomination: He exists, yet he doesn't.
• Expy:
  • The mysteryman sprite brings to mind Uboa from Yume Nikki. Just like Uboa, it's a black and white entity with a hidden RNG dictating whether or not it and its accompanying room will show up.
  • Being a scientist stuck in a prison of his own making is similar to Dr. Andonuts in Toby Fox's The Halloween Hack, who is even represented as Uboa in his overworld sprite when confronted.
• Failure Is the Only Option: In a since-deleted tweet, Toby stated that "You've all seen the happiest outcome. Neither of them could fix the machine, no matter how hard they tried. No one can."
• Ghostly Gape: One of his fragments (serving as his folder's image) looks like it might be a skeleton like Sans and Papyrus, but with that particular expression and the cracks on his face, it ends up looking more like a ghost. Given his predicament, it's probably fitting.
• Gone Horribly Right: Whatever time-space shenanigans his "creation" would have involved and whatever they were meant for ended up affecting him instead.
• Gone Horribly Wrong: As brilliant as he was, his life was cut short; one day, his experiments went wrong, he fell into his own creation, and... poof.
• Hell Is That Noise: In Entry #17, Gaster speaks over a unsettling dial-up like noise and his Voice Grunting is a jumble of multiple text-to-speech voices. In Deltarune, characters like Kris and Spamton have had their ears blasted with that same noise over the phone, but Gaster hasn't responded on-screen as of chapter 2.
• Hoist by His Own Petard: Non-villainous version. Gaster was the one who designed and built whatever he plummeted into, the damage of which was so severe that it blasted him and possibly some of his colleagues across time and space.
• Leitmotif: "Gaster's Theme"^note "mus_him" in the game's files, a song that can only be heard in a secret Sound Test screen that only features a few supposedly unused songs and locks up once the player reaches his theme. It's simply an eery arpeggio played on a piano with some backing, so jury's out on whether any other arpeggi in the soundtrack are meant to be quoting it.
• Meaningful Name: Possibly named after the Wingdings font, which he uses to speak and write. Much like the man himself, Wingdings is cryptic and mysterious, and it takes a lot of effort to memorize and understand. "Gaster" probably comes from the Old English word "gast," from which the word "ghost" derives. "Aster" is also the name of a typeface and is a genus of flowers.
• Morally Ambiguous Doctorate: He's a rather ominous doctor, between his dangerous creations and the fear of those NPCs which discuss him.
• Number of the Beast: There is data in the game for a possible battle encounter against Gaster. For some reason or other, his attributes have the number 6 in every digit. 66 being the Fun value that specifically reveals the door to Mysteryman's room at Waterfall is one factor that plays into fans assuming he is what Gaster looks like.
• Omnidisciplinary Scientist: He's an engineer skilled enough to create the CORE, the geothermal powersource of the entire Underground, and it's implied that he was engaging in experiments with Determination before Alphys, with the latter learning from provided blueprints to use the extractor in the True Lab. Then there's his investigation into matters regarding time and space.
• The Omniscient: He's been scattered across space and time. As a result, he seems to be able to eavesdrop on everything.
• Painting the Medium: Initially it was necessary for players to make a quick fix to the game's save file to enable the content related to Gaster. After a number of patches and ports this content was made available by default and expanded. The announcement of Deltarune was later made by an unknown entity who remarks they and the audience have been looking for each other for a while, and that they look forward to connect with them.
• Production Foreshadowing: It seems that Gaster's (non)existence in Undertale was meant to foreshadow Deltarune:
  • The enigmatic Entry Number Seventeen, with its talk of darkness and the "garbage noise" that Gaster talks over both becoming vaguely relevant in Deltarune.
  • The secret room 272 with the mysterious figure that says "redacted" in wingdings leads to a Sound Test, and the moment you finish listening Gaster's theme, it will say "Thank you for your feedback! Be seeing you soon!", which supposedly connects to the mysterious voice waiting for us in Deltarune.
  • The original version of Deltarune's website in December 2015, unnoticed by the entire player base back then, was a pitch-black page with a hidden message in Wingdings that changed over time. First it quoted from Entry Number Seventeen, and then it had Gaster mentioning the legend of the three heroes who oppose the Angel's Heaven:
    THREE HEROES APPEARED
    TO BANISH THE ANGEL'S HEAVEN
• The Professor: A monster who speaks entirely in Wingdings, and the most brilliant mind in all of monsterkind responsible for creations like the CORE.
• Professor Guinea Pig: He fell into his creation, transforming him into what he is now. It's unknown if it was on purpose or if it was a freak accident, but either way, he ended up becoming part of his experiments.
• Ret-Gone: Due to his name triggering a restart in the name select, the dialogue from the Goner Kid, and the lack of any characters ever mentioning him (besides the Followers), it may be the case that Gaster was not only shattered across space and time but had his history erased and no one remembers him. Of course, this is just one of many mysteries surrounding the man and no one knows for sure.
• Riddle for the Ages: While there are some "models" of Gaster that are more popular in fanon interpretation, at the end of the day, he as a character is an absolute mystery on just about every level. We have no idea what he was like as a person, what his goals or relationships were, his exact fate and how it befell him, or even what he looks like; all that is known for certain about him is what his followers tell us: he was the brilliant Royal Scientist who made the CORE, an experiment of his went horribly wrong, and he was scattered in pieces across time and space.
• Tough Act to Follow: In-Universe. One of his followers says that after Dr. Gaster's death, the Royal Scientist position stayed empty for so long because nobody could follow Gaster's act.
• The Unintelligible: Gaster speaks in the font he is likely named after, in this case, Wingdings. It probably isn't a "dialect" the player will understand, though fortunately, lots of translation tools exist online.
• Vagueness Is Coming: The elusive Entry #17 hidden in the files, in which Gaster talks about doing research on an ever expanding darkness. He then asks what two unknown people think about it.
• Voice Grunting: The oddest sounding variety of it in the game: a jumble of text-to-speech voices speaking in gibberish, only heard in the hidden Entry #17. The text-to-speech voices are actually taken from a message asking dataminers who happen upon the file not to spoil the game's secrets, which is then jumbled up for Gaster's voice. The Version 1.01 patch replaced the message with the same text-to-speech voices laughing, one after the other, which sounds pretty much the same when jumbled up.
• Wingdinglish: Uses the Trope Namer, Wing Dings, as the font he speaks through, which the River Person seemingly deems as "speak[ing] in hands".
• World's Strongest Man: According to the wiki, his datamined stats are 666666 HP, 66666 ATK and 66666 DEF. Compare this to the stats of the second strongest enemy^note 9999 HP, 8 ATK, and 9999 DEF for Asriel's Final Boss form. and you see they're all comparably paltry. However, seeing as Gaster technically does not exist in the world of Undertale, he also isn't the strongest monster.

Gaster's Followers and Goners

"However, his life... was cut short."

A group of characters that are all related to the game's internal "Fun" value; much like other Easter Eggs related to Gaster, they will only appear if it is at certain values. Additionally, if the player leaves the room that they appear in, they will not reappear. There are five characters total: Gaster Followers 1-3, Goner Kid, and Goner Clam Girl. The former three directly talk about W.D. Gaster himself. Goner Kid does not, but functions similarly to the followers. Goner Clam Girl also does not talk about Gaster, and instead appears in place of the normal Clam Girl for one line of dialogue.

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Tropes that apply in general

• Ambiguous Gender: They are never given a canon gender.
• Deliberately Monochrome: All five of them are grey.
• No Name Given: None of them are named in-game. The game files refer to them as such:
  • Gaster Followers 1-3 = spr_g_follower_...
  • Goner Kid = spr_mkid_goner
  • Goner Clam Girl = spr_clam_goner
• Palette Swap: Gaster Followers 1-2, Goner Kid, and Goner Clam Girl are all monochrome versions of other monster characters in the game, though they also have other differences from the "normal" versions.
  • Gaster Follower 1 = The ficus licker in MTT Resort
  • Gaster Follower 2 = The monster holding the donut at the Spider Bake Sale
  • Goner Kid = Monster Kid
  • Goner Clam Girl = The Clam Girl near Napstablook's house
  • Gaster Follower 3 = Double Subverted, as the "normal" version later appears in Deltarune

Gaster Followers 1-3

"After all, the old one... Dr. Gaster. What an act to follow!"

• Body Horror: Follower 3's normal appearance is revealed in Deltarune, but given their differences it seems as if the follower has lost their lower jaw, had their throat cut and their feet melted into the floor.
• Mr. Exposition: They only talk about what happened to W.D. Gaster in some form.
• Oracular Head: The "head" in Gaster Follower 2's hand is the one talking.
• Properly Paranoid: Gaster Follower 3 believes it'd be "rude to talk about someone who's listening" in regards to Gaster. Given that Gaster Follower 2 vanishes immedietely after boasting about having a piece of Gaster...
• Rhymes on a Dime: Gaster Follower 2 does this if you look closely.
  Gaster Follower 2: Alphys might work faster. But the old Royal Scientist, Doctor W.D. Gaster?
  One day, he vanished without a trace.
  They say he shattered across time and space.
  Ha Ha... how can I say so without fear?
  I'm holding a piece of him right here.
• Satellite Character: To Dr. Gaster, as they are only there to provide information about him.
• Tempting Fate: Gaster Follower 2 says they have nothing to fear from Gaster, since they've got a piece of him. They vanish immediately after they're done talking.^note Notably, his disappearance is accompanied by the same sound that plays when the "Mystery Man" vanishes. The sound was also used for Goner Clam Girl.
• Wham Line: The followers all speak of Gaster in the past tense, and the snippets of his story you hear all imply that he's dead, gone, or Ret Goned. That is, until you speak to follower #3, whose final line suggests something much stranger:
  "Well, I needn't gossip. After all, it's rude to talk about someone who's listening."

Goner Kid

"Please forget about me."

• And I Must Scream: Talks about how horrible it is that the world moves perfectly fine on without them.
• Cheated Angle: Goner Kid's horns appear at the side in both the back-facing and front-facing sprites (unlike Monster Kid, who only has a cheated angle in their front-facing sprite).
• It's a Wonderful Plot: Discussed and Played for Horror.
  Goner Kid: Have you ever thought about a world where everything is exactly the same...
  Except you don't exist?
  Everything functions perfectly without you...
  Ha, ha... The thought terrifies me.
• Mirror Self: Goner Kid and Monster Kid have their (asymmetrical) horns on opposite sides. Interestingly enough, Goner Kid's horn side does match Monster Kid's horn side in Deltarune...
• Monochromatic Eyes: Has completely blank eyes.
• Throw the Dog a Bone: Talking to them while holding an umbrella makes them feel less miserable about their situation.
  Goner Kid: An umbrella...? But it's not raining.
  Ha, ha...
  You know that does make me feel a little better about this.
  Thank you.

(Goner) Clam Girl

"Not knowing where I live is no issue. Fate finds a way."

^{Goner Form}"In life's grand scheme,, she may be why you came here in the first place..."

• Canon Foreigner: Clam Girl's goner counterpart only appears in the Nintendo Switch version of Undertale.
• The Ghost: Suzy, the Clam Girl's neighbor's daughter. Goner Clam Girl hints you might meet her soon...
• Production Foreshadowing: Mentions her neighbor Suzy. Then says we will meet Suzy soon in the Nintendo Switch port. Not too long after the port's release, Susie debuts as a deuteragonist in Deltarune.
• Surprisingly Creepy Moment: The Clam Girl, when she transforms into her goner counterpart, appears with a single, bloodshot eye in place of her head.
• Unknown Character: Clam Girl's neighbor and their daughter Suzy. No information is revealed about either of them, for all we know they could be just an Invented Individual. We do meet Susie in Deltarune, but it's not clear if this is a case of Inconsistent Spelling or not.
• Wham Line: Goner Clam Girl's appearance qualifies as one.
  Clam Girl: So you never met my neighbor's daughter.^note She calls her Suzy in an earlier conversation.
  But please don't despair.
  Because the time that you will meet her...
  [Music stops.]
  Goner Clam Girl: ... is fast approaching.^note Curiously, this text box is displayed on the upper half of the screen, rather than the bottom.
  [Disappears.]

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