Fanfic / Kris Performs Surgery

All spoilers for Deltarune will be unmarked, but spoilers pertaining to this story will be marked.

Kris Performs Surgery is a fanmade Deltarune story by PetahPetah, which began being posted to the Deltarune subreddit starting in December 2021 before later receiving an Archive of Our Own page.

Sometime after the events of Chapter 2, Rudy Holiday is diagnosed with a brain tumor. Late in the night, Kris and Susie sneak into his hospital room as he sleeps, where Kris pulls out their soul and stabs him in the chest, creating a Dark World in his body. With Ralsei joining the party soon after, the Fun Gang traverses the monster's body on their quest to destroy the tumor and save Rudy.

The series is available on both PetahPetah's Reddit account and on Archive of Our Own.

Kris Performs Surgery contains examples of:

• Affably Evil: Carci is laid-back, relaxed and polite to the Fun Gang when she first meets them, and is perfectly willing to let them do their things and hold conversations with each other while she's doing stuff on her phone, and even scolds them for keeping Rudy in the dark about the fact that he is inside his own body. She is still an Anthropomorphic Personification of Rudy's cancer that's slowly killing him, fully onboard with "Doc"'s plans to "free themselves from Rudy's body", even if it means his death. Even when she had an opportunity to easily destroy the Lightners, she agrees that it wouldn't be fair and leaves the Lightners to explore the ass while she resumes her boss's plan.
• All Bikers are Hells Angels: The Hershey's Angels are a gang of literally shitheaded bikers who attack the Fun Gang on their leader Rexum's orders. They have a Heel–Face Turn after the Fun Gang spares Rexum, however.
• Amphibian at Large: The Sucramphibians found in Rudy's small intestine are large frog-like Darkners.
• Animal-Vehicle Hybrid: Rexum, the leader of the Hershey's Angels, has the upper body of a bull and the lower body of a motorcycle.
• Ass Shove: Carci banishes the heroes into Rudy's ass, along with Rudy himself by accident.
• Bait-and-Switch: After Kris and Rudy reach the latter's stomach and find Susie alone, she says that she "couldn't save him" and that she attempted to jump the lake of stomach acid. At first, it seems like Ralsei fell in because of Susie's recklessness, but then he walks in from the other side of the screen, and it's revealed that Susie's really mourning her motorcycle.
• Beware the Silly Ones: Carci is an Affably Evil sort who is just as Laughably Evil as Leuka, but she's very much the smarter and more powerful of the two. She nearly delivers a Curb-Stomp Battle to the party (and kills the Hershey's Angels) when she thinks they badly injured Leuka.
• Big Bad: "Doc", the brain tumor that Leuka and Carci work under.
• Big Boo's Haunt: There is a graveyard within Rudy's spleen that is haunted by ghosts made out of blood, which the Fun Gang must traverse through to reach the brain and Doc. The gravedigger of said graveyard claims all spleens are haunted.
• Big Damn Heroes: At one point, the gang finds themselves surrounded and outnumbered by Cellachimorphas, who ready an undodgeable attack.... until one of them is hit with a "Ha-Doe-ken" by Rudy, causing the rest to flee.
• Blatant Lies: While trying to leave Rudy's ass, the Fun Gang finds the way forward blocked by a giant piece of poop. Ralsei insists it's a "weirdly shaped boulder" and nothing else, even after Susie points out that it literally smells like crap.
• Blood Is the New Black: After falling off the raft and into the blood river, all of the Fun Gang are covered head-to-toe in the stuff without much comment, due to the fact they can't exactly do much about it at the moment. After meeting up with Rudy and finding the car wash, they're able to clean it off, much to Ralsei's relief.
• Convenient Escape Boat: Early on, the Gang's path gets cut off by the blood river, with Susie suggesting that they swim through the blood instead (with a rather enthusiastic look on her face)... until Ralsei points out there's an "instant reindeer raft" next to the path, allowing them to progress without having to swim.
• Cthulhumanoid: Carci resembles a humanoid being that possesses an octopus-like head, with tentacles covering up the mouth.
• Dark Comedy: Rife with it, from Rudy's pancreas shutting down while he and Kris are navigating it, to the Fun Gang using his stomach ulcers as trampolines (and promptly making them burst), to Susie considering stealing Rudy's liver for the excess booze.
• Dung Fu: Carci attempts to squish the gang with a giant ball of poop (which she claims to be a rock).
• Early-Installment Weirdness: Kris's dialogue is fully visible in the first three episodes before later episodes reverts them back to a Heroic Mime whose dialogue can only be inferred through options and the other character's responses.
• Even Evil Has Standards: Though Carci is a representation of Rudy's cancer that slowly kills him, she is still appalled by the fact that the Fun Gang kept Rudy himself in the dark about the fact that he's inside his own body.
• Failed Attempt at Scaring: In the graveyard within Rudy's spleen, a blood ghost attempts to Jump Scare the Fun Gang by suddenly popping out of the ground and "BOO"-ing at them. This fails to startle them since none of them are afraid of ghosts; after all, one of their Hometown's police officers is a ghost as well.^note Though this doesn't explain why Ralsei wasn't startled as he's not from Hometown.
• "Fantastic Voyage" Plot: The entire premise revolves around the Fun Gang entering Rudy's body to defeat a tumor growing in him. However, unlike most examples, this does not involve any shrinking down or ships to swim through their body, as Kris simply opens up a Dark World in his chest. It appears that depending on whether they spare or kill certain enemies in Rudy's body will affect his condition when they seal the fountain.
• Fartillery: Rudy's ass includes various fart geysers that the Fun Gang need to navigate around.
• From Bad to Worse:
  • Played for Laughs. After being propelled up a platform by a massive fart geyser, the gang ends up finding themselves in the middle of a bunch of more fart geysers.
  • Over the course of the story, it becomes clear that Rudy suffers from far more health issues than just his brain tumor, including blood and cell cancer (Leuka and Carci, respectivily), a parasite infestation (Peris, amongst others), elevated blood sugar levels, stomach ulcers, kidney stones, and cirrhosis (liver scarring).
• Gratuitous French: Peris, one of the parasites invading Rudy's body, randomly peppers her speech with French words. One of her attacks in her Boss Battle even requires Kris to choose the correct spelling of a French phrase she says to avoid getting hit by spikes.
• Guest-Star Party Member: Rudy starts joining Kris in battles after Susie and Ralsei drive off on a single bike (there were only three bikes, so two had to share one) and they're unable to catch up with them because their bikes were eaten by Sucramphibians. He stays in the party even after reuniting with Susie and Ralsei.
• Hand-or-Object Underwear: Ralsei uses his hat to cover up his body after his clothes are accidentally ripped away by Susie.
• Hand Wave: How is Rudy inside his own body? His body was split in two.
• How Is That Even Possible?:
  • After being banished into his own ass, Rudy questions how that's even possible.
  • When Rexum somehow drives his motorcycle backwards to initiate his High-Speed Battle, Ralsei asks "How does that even work?"
• Hurricane of Puns: Rexum lets a Toilet Humor-themed one of these loose while talking about Rudy.
  Rexum: Hey, that old fart's past his glory days, okay? Rudy used to be hot shit back in his younger years! But ever since he settled down, the geezer's gotten soft! Trading in his trusty hog for some family car!
• Indy Escape: Carci invokes this with a giant ball of poop. When they escape, she asks what they thought of the detour.
• Inevitable Waterfall: While riding the raft, the gang ends up going down a waterfall (or in this case, a bloodfall) and being sent off their raft as they fall.
• Internal Reveal: Rudy discovers that he's somehow inside of his own body when Carci reveals that she sent them to his ass, something the heroes deliberately kept themselves from telling him. Carci calls out the heroes from keeping him in the dark and even leaves them alone so that they could explain to Rudy what's going on.
• Jump Scare:
  • At one point, Carci suddenly pops out from behind one of Rudy's kidney stones, startling the Fun Gang.
  • In the graveyard within Rudy's spleen, a blood ghost suddenly pops out of the ground and screams at the Fun Gang. Subverted in that it doesn't startle any of them.
• Killer Bear Hug: The party defeats Leuka by hugging him very tightly, with the excessive hugging resulting in the blood he took in spraying out of his pores.
• Large Ham: Leuka speaks in very loud and dramatic over-the-top manner.
• Laughably Evil: Leuka and Carci; Leuka is a Large Ham Ineffectual Sympathetic Villain with No Indoor Voice until he gets embarrassed, and Carci is an Affably Evil Phoneaholic Teenager who speaks in all lowercase letters. They're also embodiments of two of the cancers that's killing Rudy.
• Let's Get Dangerous!: Carci looks as if she couldn't care less about the plan to destroy Rudy, but when she sees that her brother is in no condition to fight, she interferes with the heroes the moment they try to leave and banishes them to the ass. She decides not to destroy them instantly since it's far too early in the story.
• Literal Metaphor: The Fun Gang spares the dung-headed Hershey's Angels by making them and their bikes shiny. As Susie points out, they polished the turd(s).
• Make My Monster Grow: When preparing himself to fight the Fun Gang, Leuka grows himself to colossal size by absorbing Rudy's blood.
• Meaningful Name: Leuka and Carci get their names from Leukemia^note A cancer of blood-forming tissues. and Carcinoma^note A type of cancer that starts in cells..
• Mix-and-Match Critters: Tinny, the owner of a store in Rudy's small intestine, is an anthropomorphic pig with reindeer horns.
• Mobile-Suit Human: The Pancry Chefs are humanoid robotic chefs controlled by rat-like Darkners via two levers where their head would be. No points for guessing what that's a Shout-Out to.
• Non Sequitur, *Thud*: Ralsei does this after getting bonked in the head with a coconut.
  Ralsei: K-Kris, why are you wearing a dog collar and hoodie? You're not a bad doggo...
  Susie: (confused) ...Bad doggo?
• Not So Above It All: Carci seems to be the more serious of the pair, having a creepy looking move that banishes the heroes (and Rudy) to Rudy's... ass? She later follows them in there and takes a nap while the heroes come clean to Rudy that they're inside his body.
• Not What It Looks Like: When Leuka gets trapped under a boulder, the Fun Gang have to get help from the Hershey's Angels to save him. Unfortunately, Leuka was stiffened from being stuck for so long and couldn't move, and to make matters worse, Carci came and assumed that everyone ganged up on her brother, causing her to Turn Red and almost kill everyone. It takes Leuka explaining what really happened to him for Carci to realize that Leuka's injury was her own mistake.
• Our Ghosts Are Different: The graveyard within Rudy's spleen is haunted by ghosts made out of blood.
• Parental Sexuality Squick: In episode 101, Carci mentions that Optica (the Anthropomorphic Personification of Rudy's frontal lobe) is forced to watch all of Rudy's repressed memories. When Rudy questions this, Carci gives "the time you walked in on your parents making you a baby bro when you were four" as an example, horrifying Rudy.
  Rudy: ...I did not need to be reminded of that.
• Plague Doctor: Doc wears a mask of one, which is fitting both because of his name and the fact that the mask is considered symbolic of death, and he's a personification of a brain tumor.
• Primal Scene: When Rudy questions what repressed memories the Anthropomorphic Personification of his frontal lobe watches, Carci brings up (much to Rudy's displeasure at being reminded) that he walked in on his parents "making (him) a baby bro" when he was four.
• Redemption Equals Death: The Hershey's Angels have a collective Heel–Face Turn after the Fun Gang spare Rexum, but Carci kills them off not long after.
• Red Oni, Blue Oni: Leuka is the very hammy, boisterous, and Hot-Blooded Red Oni, while Carci is the quiet and relaxed Blue Oni.
• Red Shirt Army: The Hershey's Angels are killed by Carci shortly after the Fun Gang spared Rexum, showing that as affably and Laughably Evil as Carci is, she can still be a serious threat if sufficiently provoked.
• Reverse Psychology: When the Fun Gang is fighting Leuka, Kris and Ralsei decide to beat him by hugging him. Susie refuses to join, and Ralsei decides to nudge her in by asking her to confess that she's afraid of giving hugs, prompting her to join into the hugfest in a desire to prove him wrong.
• Rivers of Blood: Literally. Rudy's bloodstream takes the form of an entire river system in the Dark World, which the gang must ride a boat on to progress.
• Rock Monster: One of Carci's "puzzles" has her use a "Berserker Crown" she got from Rouxls Kaard to turn one of Rudy's kidney stones, which became literal rocks in the Dark World, into a ferocious monster to fight the Fun Gang.
• Ruder and Cruder: Not too much compared to the actual Deltarune, but Susie's not hesitant to say "Bitch" or drop a few F-Bombs in this series.
  Susie: Me and my big fucking mouth.
• Seeker White Blood Cells: The first enemies Kris and Susie encounter are Rudy's white blood cells who took the form of fish-based Darkners known as Cellachimorphas. They're spared by reeling them in with a fishing rod.
• Shout-Out:
  • Rudy's Dark World outfit is based directly on Ryu, complete with Hadoeken!
  • The Fun Gang beats up a car, complete with a high score, just like Street Fighter II.
  • The flavor text for the SpdBoost ACT usable during the Rexum fight says "Gotta go FAST".
  • In Episode 17, Rudy admonishes Kris for messing with him and Noelle's Dragon Blazers III game, a reference to Noelle and Rudy play Deltarune. Of course, everyone is confused (the series don't take place in the same continuity anyway).
  • Rexum somehow manages to accelerate backwards, in what he describes as "'Big Rexum: Over The Road Racing' style", referencing the bug in that game which allows uncapped acceleration in reverse.
  • When given the opportunity to grab a carrot as a snack for later, Susie tells Ralsei "Hell no, I don't want any damn vegetables".
  • The Pancry Chefs are humanoid chef mechas piloted by rat-like Darkners via two levers in place of their heads.
• Suddenly Speaking: Kris, unlike in the game, gets lines of dialogue in this series, with their own textbox portraits too. Inverted later on as of Episode 4, where Kris goes back to being a Heroic Mime.
• Toilet Humor: Mainly in Rudy's ass and kidneys, naturally. The former contains various fart geysers and "boulders" that halt the gang's progress, and they have to wade through "mud" that Kris unfortunately ends up falling into, traumatizing them. In the latter, well... see Urine Trouble below for Susie's own moment of suffering...
• Urine Trouble: At one point in Rudy's kidneys, Susie's corner-cutting during a mandatory puzzle leads to her dropping a key into the river of urine running through the area. No points for guessing what the poor dragoness ends up having to do next.

  Susie, with Hidden Eyes: ...There better be another car wash behind that gate.

• Visual Pun: Doc has crab claws; "cancer" literally means "crab-like" in Latin, and he's an embodiment of Rudy's brain tumor.
• Wardrobe Malfunction: While Kris and Susie are fighting the Cellachimorphas for the first time, Ralsei approaches from behind to greet them, but is unnoticed as Susie flings her fishing rod back, causing the hook to get stuck in Ralsei's clothing then flinging it away, ripping his clothes off. It's only after the battle that they notice him, albeit naked and covering himself up with his hat. He gets his clothes back in the next episode.
• Wham Shot: The shot revealing that Rudy is somehow inside of his own body after it was turned into a Dark World. How this is possible isn't elaborated on, nor does the party question about it.

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