Undertale Stories

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

(TW: unaliving thoughts and memories at the beginning. It gets better over time, don't worry! Trauma is difficult to overcome...) You didn't want a second chance. You didn't want to survive. You wanted the sweet release of death. But it seemed like the universe was far too cruel to allow you even that. It took away your memories, your free will to choose whether you live or die...hell, it took the one thing in life you owned! Your own name! And now it seemed like you had to live yet another cruel life, doing things you never wanted done to others. But...at least you could do things your way. Maybe this second chance wouldn't be so bad... (Reincarnated as Nightmare Sans, but unlike other stories, you have no clue what Undertale even is) (WE REACHED NUMBER 1 IN THE UNDERTALE TAG YOOOOOOOO) (9/13/25)

Not every story has a happy ending. Some... are forgotten before they even end. Abandoned characters. Incomplete worlds. Destinies that never reached their conclusion. But... what if there were a place where all of this could continue? Legend has it that there are two apples: the Apple of Positivity... and the Apple of Negativity. Two opposing forces. Two fates already known. But no one speaks of the third. The one that should never have existed. In a refuge hidden between universes, where not even the guardians can see... broken stories find a new home. Or remain trapped... between what they were... and what they never came to be. An original AU inspired by Undertale, where even the forgotten can still change everything.

What happens when the Gaster Gang handle a human child situation? Read and find out! Based from Bun-bunmuse art story. ps. the reader is 5 year old girl ?

I have too many memes so here

TW: Swearing and slight gore Y/N reincarnates in the anti-void as a Voice... Will he befriend error or will they make them hate their guts? And will they meet other people? Only time will tell. Hello, this is going to be my first book and idk if it's going to be good so meh :v This story was inspired by transported as a voice by Virus_bOi, I obviously do not own undertale and I don't keep up that much with the fandom, so some personalities might be different, but hey. I can just say that it's a different multiverse ¦ ] The cover image is from Shira Wolfiecute on tumblr

Have you ever thought about what it would be like to be.. Sans? Be Papyrus' lazy and playful brother? Be a comedian with endless jokes? Be the mysterious judge? Be well-liked? You envy him. You wanted to be him. Yet nothing could've prepared you for what's coming. . . . (WARNING, THIS IS A MIX OF CANON AND FANON FACTS. THERE MIGHT BE THINGS YOU DONT LIKE BUT JUST BE THE BIGGER PERSON AND TOLERATE IT. THIS IS NOT MEANT TO BE TAKEN TOO SERIOUSLY AND IS INTENDED ONLY FOR ENTERTAINMENT.) (Cover made by me. As you can see, I made that thing on IbisPaint. I understood nothing about making book covers and I messed up on the proportion many times so I gave up and that's how the cover came to be. Idk how to shade and make backgrounds/landscapes btw) (Tbh I wished I made this far earlier because it's late 2025, no one is going to read this pile of nonsense. 😭) YOU GUYS HAVE AN OPTION TO CHOOSE THE DIRECTION OF THIS STORY THROUGH FREQUENT POLLS I MADE!!! First thought of and made on 1st Dec 2025 Posted on 6nd Dec 2025 cuz I was feeling confident for that hour. I can proudly say I've been doing this book since last year hahhahahahahahaha (get it cuz I did this thing is Dec 2025 and now is Jan 2026?) I made the cover btw

"After countless resets, Papyrus has his role down to a science. But everything changes when he's thrust onto a strange new stage: the Surface. In a world where humanity wields 'Quirks,' Papyrus befriends a young Izuku Midoriya and sets his sights on a new goal. By becoming a top Pro Hero, Papyrus hopes to finally secure a future for his brother and all of monsterkind." Ps. I want to give you all a little announcement a good friend of mine you all know dreadwing346 on fanfiction.net and here on wattpad is helping me to write this story and we both agreed to put this story on a different fansite known as Ao3 under the username Dreadwing.

A/n: I got some inspiration from another story, I'll try not to make it a carbon copy. Gremory Rose, to be exact. The forgotten child. The Cursed One. Such cruel names to give a child. Alas, that's what Y/n Gremory had to endure for so long... Until he found an escape, to somewhere THEY'D never find him... The Void...

so I oh ways want to make a reborn as killer sans, but we're mentally unstable, of course, due to the rest and our past memories, which we can't remember what we were anyway! We know everything and everyone, so why not mess with them. This going to me fun!!!

Reborn as the guardian of positivity, you find yourself in a strange new world, uncertain of what it may hold. Navigating it isn't easy with gods like Nightmare and Error trying to strike you down every step of the way. But unlike the previous Dream, you have nothing to lose, and are determined to forge a better path than the soul whom you have replaced.

Timeline after timeline, what if there's a human girl who remembers it all..? [Xtale Chara x OC] I HAVNT SEEN A GOOD COMPLETED XCHARA STORY (thats been updated recently) SOOOO IM MAKING ONE HOPE YALL LIKE IT AND XTALE IS STILL SOMEWHAT RELEVANT -_-

An experimental fic I have featuring my own Undertale AU, Humantale, may or may not continue it. (Credit to the cover goes to xchocokills on Pinterest.)

[no ships rn] Killer Sans never had a choice from the beginning. Passed on from one to another, from Chara to Nightmare. Out of a frying pan and into the fire.. Honestly, you're speechless by his backstory. It's too tragic! Hes a bit too miserable for your liking. Though, reading the good ending for him made you felt somewhat better. Watching Killer and Color Sans rebelling against Nightmare was satisfying after seeing Killer get utterly destroyed by him in the previous comics. If you had to rate Sanses on which one you never want to be, Killer Sans would be at the top. After all, he hallucinates, hes mentally unstable, emotionless most of the time, usually slaving away for his boss and the whole 9 yards about his backstory. Unfortunately, you look at the knife in your hand and the dusty Snowdin then at the two souls beside you. Killer and Chara both arguing, the overwhelming voices around you made it unbearable already. [thought of on 8th March 2026]

Corporal Adrian Shephard, a US Marine Corps soldier within the HECU division, was sporadically shipped off to Black Mesa for a seemingly simple job: 'cleanup duty'. Despite every single odd stacked up against him, the marine somehow manages to survive the dangerous, alien-ridden facility and, after being detained by the ever-so elusive G-Man, is then suddenly assigned a mission many years later... To the UNDERGROUND! Accompanied by Chara Dreemurr, the first fallen human turned apparition, the two journey through the Underground civilization for one, very specific goal... but what exactly was it? And was that all there was to it? In... time, all will be revealed.

Sans. The weakest, yet the hardest boss to beat in undertale. At first glance, he seemed like nothing but a comedic, lazy skeleton. But if you push far enough, if you decide to take the genocide route... He will show you HELL. Now imagine him free from the game's restriction. Disclaimer : I do not own any art i use in this story or any characters here. Undertale is owned by Toby fox.

sOoo I've had this idea where they have soul mates. Like everyone is born with a half heart necklace. Every time the person gets near their soul mate it will heat up as they go farther away it gets colder. EEE I couldn't decide wether I wanted this to be errorfresh or kustard so not many people like errorfresh so it's kustard ;-;

In a superhero society where those who shout the loudest usually steal the spotlight, true strength sometimes prefers silence. Meet Ayato Saishiki. He doesn't have infinite super strength, he doesn't generate colossal explosions, and if given the choice, he would spend his days in absolute silence with his precious noise-canceling headphones. However, he is the wielder of the Soul Spectrum-an overwhelming Quirk that manifests as seven hearts of pure light floating around him. Each color is a virtue; each virtue is a devastating weapon. But this power demands a lethal price. To avoid frying his own nervous system with Chromatic Exhaustion, the stoic boy in the neon tactical coat keeps his eyes closed, his ears covered, and his emotions strictly locked away. Admitted to the prestigious U.A. High School and quickly thrown into the eye of the storm as the Class Representative for the chaotic Class 1-A, Ayato views heroism differently: the battlefield is a chessboard, villains are mathematical variables, and the safety of his classmates is the absolute rule of the game. Between loud peers, rigorous lessons, and the constant threat of his own physical limits, the silent strategist will have to prove that sacrificing his own mind isn't the only way to be a shield for those he cares about. The board is set. The pieces are in position. And the seven souls are about to shine. Saishiki Ayato's game has just begun. ((Note - I am not the owner of My Hero Academia or any of their characters, the entire credit goes to the original creators.))

This isn't a normal Y/N story the bad sanses do a raid on an illegal auction of many rare, dangerous, and illegal things. but after the dust settles, killer finds what he believes to be a weird mutated cat and decides to take it back with him art by me. my first book, and feel free to correct my spelling in the comments Y/n means your name Y/fc means your favourite colour Y/fm means your favourite type of meat Y/hl means hair length Y/hc means hair colour Y/sc means skin colour Y/ec means you're eye colour

(Cover by Hetiru on Deviant Art.) Several years after Monsters returned to the surface, this story follows Y/N, a quiet and reserved highschool student just trying his best to manage his day to day life. Between the bullies, lack of a family or friends, and two new transfer students making everything even more difficult for him, Y/N decides he doesn't need to deal with it anymore - and finds himself at Mt Ebott. ⚠️ WARNING ⚠️ This is a somewhat dark story. If that's not your thing, or if subjects like depression, suicide, and self harm are difficult for you, please do not read this. Otherwise, please enjoy! (Once I actually start adding chapters of course.)