Undyne Stories

Abandoned on Mt. Ebott at the tender age of five, young Harry's unsurprisingly died, but Death's always had a weird relationship with his variant... Meanwhile, before Flowey's revival as souless talking flower, Sans makes a discovery under the mound of snow, Papyrus has always wanted to be a big brother anyways. *Edited Summary (29/09/2025)

In this AU, Undertale monsters live amongst humans in the One Punch Man verse. How will it all play out? (THIS IS DIFFERENT THAN PUNCHTALE!!!) As an AU, characters may differ from their canon counterparts.

This story takes place after the events of the pacifist ending of Undertale, where all the monsters have already left the underground. However, that won't stop problems from starting again; Frisk and his friends will have to face a new threat. DISCLAIMER: This story is based on the fact that the first human fell underground in 2015 and the last in 2060. Here, Deltarune is a sequel to Undertale; therefore, Posttale is not a copy of TobyFox's creation, but an adaptation, or what is also called an "AU." Because of this, there will be things that are different from canon and adapted to my personal preference, with no intention of disrespecting anyone; for example, the gender of the humans: Kris: M Chara: F Frisk: M Don't like it? You can leave. Understood? Great. Contributors: @Fwrevy #Deltapad • Undertale and Deltarune are property of Toby Fox. • Images used in the story are property of their respective owners or made with AI. *#27 in the "Undertale" category 6/13/2026* *#3 in the "Deltarune" category 3/3/2026*

Working at a luxury hotel has its advantages- the pay, discounts, seeing celebrities. It's not all sunshine and rainbows, but you enjoy it! As someone who overanalyzes things and processes things different then most normal people, you find the mind numbness of the job very relaxing. Not too exciting, not too boring, just nice and simple. Unfortunately, you're really good at your job. And that causes you to accidentally overhear some intel- causing you to be kidnapped and sold at auction. What happens when a perfectly composed and professional monster loses his rational thinking in her presence? What happens when they come together to stop forces beyond their control- beyond their power? _________ Art doesn't belong to me.

After escaping the Underground and getting clipped by a truck, an amnesiac Sans ends up in the home of a vet, a doctor, and their daughter. He's certainly nothing they've ever seen before, but they can't just let him suffer either, so he becomes the unlikely son. So when Frisk falls into the Underground, Sans must return home to the place he was born and raised. Can he and Frisk free monsterkind from the mountain, or will they make a home Underground with the family Sans lost long ago?

Lance lived his normal life, battling monsters, annoying clay, life was perfect. But he made a mistake that changed his life. Now he's in another dimension, has a crazy do-it-over power, and has to battle one of his friends. THIS IS AN UNDERTALE CROSSOVER (or killer tale crossover), since someone had to do it. This my first book/au so hope you all like it!

It's a fall into darkness... a world of starving monsters. All that would do anything to survive. And that includes catching a human like you. Horrortale. Inspired by Undertale, based on the Horrortale universe. Credits to Toby Fox and Temmie Chang for their respective characters and Sour Apple Studios for creating Horrortale. Just a small warning that there are some grusome imagery. Continue reading only if you're okay with it! (Art credited to it's respective artist.)

Saitama gets stuck in the Underground. Well, this'll be interesting!

Following the aftermath of the Undertale pacifist run, something strange occurred. Frisk's ability to reset is gone, and odd occurrences happen, targeting Ebott city and beyond. Without the ability to reset, the entire world is on the line. However, one lost entity finds its purpose.

One day, Y/N was playing Undertale. Y/N finished the game, both genocide and pacifist. After the second pacifist ending, you wondered how life would be like IF the monsters actually were real. If the monsters would actually roam around and act as humans. That thought soon changed. ( Book Cover Picture is NOT Mine. I found it on google. Credits to the owner. )

Crystallize [kris-tl-ahyz] refers to the process where a liquid or gas transforms into a rigid, structured crystal lattice. Or... I look at my other two Avallon and thought 'Yeah I could do more angst with these bois.'

Your fist clenched, unsure if you should punch the living daylight out of him, "Who said I was playing your game." "you don't have to say anything, you're automatically playing," He took a step back and walked past you with a lazy wink. "but at the end of every game, i always win. and you better believe it, sweetheart, i'll be leaving a permanent scar on your heart." [Title used to be "Commitment"] [Credits to: Undertale by Toby Fox Underfell adopted by the community Artists, editors and singers/band]

Here is the different book of covers with different songs recorded by the Classroom Musical Gang.

This is now for Soriel Trash like me :P DONT JUDGE ME OR THESE STORIES IM A 13-YEAR-OLD EMOTIONAL BALL OF FEELINGS. Ahem. Now that that's out of the way, I hope you enjoy my stories! Also, If I (for some reason) ever write a short without much soriel in it, I'll let you guys know. -Fernpelt UNDERTALE BELONGS TO TOBY FOX NOT ME. MY NAME IS NOT TOBY FOX 'KAY?

Drifting in the desolate remains of a Genocide Route, King Asgore Dreemurr has been resurrected! After learning of the fate of himself and his people, Asgore is given an offer that will set him on another path. But will that path be what he truly desires?

An accident at the C.O.R.E as a boy caused Papyrus to go blind. He never told anyone. He didn't plan on ever doing it. Until he makes it to the Surface and meets a nice girl named Nashira. Nashira seems to be able to read him like an open book and he doesn't know what to think... or what to feel. Original idea is called Tag and can be found in the Fandom Short Stories book.

You fall And fell So small and frail You met with a yellow flower He thought of you as a coward On that very day you got a new mother But who would have known that you have also gotten a not so soulless brother

A bunch of undertale comics

New Soul - Sans x Female! Gem! Reader (DISCONTINUED) You're a gem. Two weeks ago, you've arrived on Earth. You've came to start a new life and go on actual exciting adventures. You've came to be free. To start off you're first ever adventure on Earth, you went to climb Mt. Ebott. Of course, you end up falling into the opening of the mountain. Next thing you know, you're meeting all different types of monsters. Goats, fish, robots, you name it! Your first encounter with a certain skeleton didn't turn out so well... but that was in the past. You guys are close now! Ah, but you're not gonna get a happy ending just like that. Something will happen. Decisions will be made. You have to be careful with your choices... because the fate of you and all you monster friends is in your hands... Highest rank #5 in pacifistroute #1 in genocideroute #2 in reset

WARNING: This is not the official book adaptation for the 2015 video game Undertale. All characters, settings, and original plot all belong to Toby Fox. If you have not played the game, I would kindly remind you to play the video game. (It's one of my favourite video games). This is only a fan-fiction book for my writing skills and to deepen the Undertale themes from the game.