Gaster Stories

This is a story before the last human fell around the time Chara was still alive and well. Humans were not being hunted till the adopted prince's passing, however with a...

Well, here we are again, huh? I guess want to know what the Undertale crew talks about when nobody is looking. Ok, then! Come on in! Let's get all up in their biiiiiiiiz...

--- > In a world where only women are born with quirks, society treats men like they're worthless. Izuku Midoriya is bullied by his sister, ignored by his mother, and...

Error didn't know what to expect after being pushed into the Void. He didn't expect to be transformed into a teenager. He didn't expect to fall into a world full of drag...

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 ?

All of the AU sanses (Except Classic) are up against a strong enemy and is in need of more help from more sanses , which they can't afford because the only sans missing...

Image a world where there was no war. Toriel and Asgore never divorced. Gaster never fell into the void. The genocides never happened. Everyone is happy. That is this wo...

At the end of every genocide run, Frisk duels with Sans and wins. However, what if Sans begins to care once more and takes the blow in replacement of Papyrus? Who will l...

The reader wakes up to a new life as a monster skeleton. In a new world, that's filled with monsters, humans, and magic. But instead of living their new life to the full...

I do now ship this.. maybe? idk The sans aus have been trying to find classic.. (for some apparent reason) he is the most powerful sans. and the only hope to defeat to v...

(YN), an 18 year old teenager that lives in a dimension called Undertale, alongside with his parents; Queen Toriel and King Asgore. His parents were then worried about h...

When Weiss Schnee Gets Hit by Cinder Falls Fall Maiden power she falls into the abyys and ends up in the anti void instead of The Ever After where she meets Error!San's...

I don't really know, just an attempt. Might go well, might not. We'll see.

"Do you not want to go back home? To the surface?" °°°°°°°°°°°°°°°° "No." °°°°°°°°°°°°°°°° "Why?" °°°°°°°°°°°°°°°° "Because my home i...

The RiverPerson is truly a mysterious monster, only known as to sing and to help you travel place to place, they were an NPC, surely he wouldn't be him, right? Oh how wr...

I walked along the street. Everything was perfectly normal. The sun was warm, a soft breeze swept through my short (h/c) hair. Then the sound of glass shattering reache...

A series of semi-realistic scenarios including a handful of Undertale characters. In otherwords, stick around. ... Please.

Gaster is working on a new experiment in his basement/lab at home. Sans and Papyrus are out of the house for the moment...and Gaster is in for quite the surprise from wh...

The one that made it the furthest in the underground, perseverance. Perseverance had beaten almost all of the monsters in the underground from papyrus to sans and undyne...

Harry Potter was master of death, he was use to ending in other universes/timelines. This time he ended up as a skeleton monster Remake of Death and wingdings om ao3 201...