Gaster Stories

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

It was just a peaceful day in Snowdin. Everyone was just doing what they normally do in the underground. The Nicecream guy kept selling, monster kid was playing around...

You are the elder brother of Frisk. I'll explain later. This book will not be updated for a while, sorry. Completed: December 2nd, 2020 SC Book# 12

Gaster, the Royal Scientist created best of his invention. Core of Hotland. But there was an accident that ended his life. As a result of the crash at launch, he fell di...

There was one's a high school girl 16 year's old a big fan of Undertale. She decided to make here own Oc of Sans of her self and make a story... While the girl was waiti...

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 ?

This doesn't 100% follow the original Xtale story even before the babifacation of Gaster. When a pure yet genius soul dies at the same moment one of Xtale Gaster's over...

Sans has lived through countless timelines. He's seen the kid make friends with everyone, only to give up in the final moments. He's seen the kid killed, over and over a...

'When I was 13, I killed someone. By accident of course... It was the day I found out I possessed some type of power.' You kept it to yourself for years until one...

What if Sans only got Papyrus away from Gaster? What would happen if Alphys found him trapped years later? Can they teach him to be a normal monster, or will he forever...

Y.N. Gaster one of Ozpins best friends. But soon to be enemy. Due to there differences Ozpin trapped Y.N. in the void where he stayed for years. Y.N. had tried many time...

You've seen Sans past. So what is Gaster's? What about Grillby's? Welcome to the Prequel of Forgotten History!

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 t...

(My first story so sorry if there's bad grammar) The Rose family had never been more positive after they had there children. Plus each child had there own dreams. Ruby w...

(Y/n) Gaster is a human with powers that no one knows about. What would happen if he were to be living with an alien girl? To Love Ru isn't owned by me. Sans from Undert...

~o0o~ Book 1 of the "Better Times" trilogy ~o0o~ (Book two: "A Name to Remember") (Book three: "No One is Happy with This") There was a tim...

DRAMA, ACTION, BLOODSHED... Love? After erasing hundreds and hundreds of timelines, Chara is suddenly stripped of her abilities. She's forced to lead an everyday life i...

Yeah sorry gained an idea on if someone became swap Gaster Also they may be apathetic or just confused on their feelings and MAYBE Autistic, I may be a bit wrong on ap...

I don't own Undertale or any images.

Even though the Underground is now empty, except for some people, you still stupidly managed to fall in the once prison for monsters. Who knew you would get away from th...