Gaster Stories

1.2K Stories

The Skeletal Hero: Karmic Judge by A_Toast1
The Skeletal Hero: Karmic Judgeby A_Toast
Complete! The player has just finished fighting sans and has left him to die. As sans turns to dust he sees a flash of light before everything goes black. He then wakes...
After the War [An Undertale FF] by Authortale
After the War [An Undertale FF]by вaѕιc тraѕн
Have you ever wondered what happened before the Seventh human fell. Before YOU...came to the Underground? The person that manipulated time and space, who played with the...
Undertale:Secrets by ItIsComic
Undertale:Secretsby Comic
Sans has had an interesting past. A past that even his beloved brother barely even knows of. A past that he wishes could remain a secret. But when the questions start be...
Child of the Void (Gaster! Reader x RWBY x Highschool DXD) by KyogreKing120
Child of the Void (Gaster! KyogreKing120
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...
The Ghost Above Me (Gaster x Reader) by xsfolia
The Ghost Above Me (Gaster x everail
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...
Gaster gang x child reader  by Niharafroon
Gaster gang x child reader by Niharafroon
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 ?
The Fallen Player by Treekami
The Fallen Playerby Tree
We follow YOU, the Player, on this epic Undertale story. You get sucked into the game on your computer and have no idea what to expect. Will you be able to get back home...
GravityTale || Undertale/Gravity Falls Crossover|| by Kitsynii_
GravityTale || Undertale/Gravity it's best to call me Runa
{ Chara and Frisk are girls in this story} Gaster attempts to save Frisk and Chara during the fight with The God of Hyperdeath and bring them to safety. But you know how...
The Faults in Our Souls ~ Gaster x Reader (Under editing) by _T3chn0_
The Faults in Our Souls ~ Gaster _T3chn0_
"Do you not want to go back home? To the surface?" °°°°°°°°°°°°°°°° "No." °°°°°°°°°°°°°°°° "Why?" °°°°°°°°°°°°°°°° "Because my home i...
ᴛʜᴇ ʀɪᴠᴇʀ'ꜱ ʀᴇɪɴᴄᴀʀɴᴀᴛɪᴏɴ -INDEFINITE HAITUS- by Zego-San
ᴛʜᴇ ʀɪᴠᴇʀ'ꜱ ʀᴇɪɴᴄᴀʀɴᴀᴛɪᴏɴ 【「ZEGO SAN」】
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...
Sans' Daughter by internetsansation
Sans' Daughterby Snas
(I'll make a real description one someday) But basically it's what would it be like if sans adopted a daughter after the barrier broke (I'll make a real cover someday) :...
Undertale Scenarios by InWolfsClothing
Undertale Scenariosby In Wolf's Clothing
A series of semi-realistic scenarios including a handful of Undertale characters. In otherwords, stick around. ... Please.
Undertale The nameless soul (Sans X sister!reader) by GasterIZcallin
Undertale The nameless soul ( Doc W.D.
Long before Frisk ever fell down to the underground... Before Gaster got lost within the Core... He found something... or rather someone of great value to him ...someone...
Handplates Gaster x Subject 3! Clever! Tween! Reader by EmilySkelewolf
Handplates Gaster x Subject 3! Lady of WIP
Here ya go pplz. Tween: Short for Tweenager: 8-14 years old (I know, weird)
Papyrus x Reader: A love to remember. by Sp3nce23
Papyrus x Reader: A love to Sp3ncer
Art is not mine but it's super cute Credit for art to: Skirtzzz Art Hope you enjoy X
Divided [ Sans X Reader ] by morrow-
Divided [ Sans X Reader ]by space sloth
Almost four years marking the anniversary of monster kind reaching the surface, the human ambassador Frisk goes missing. Severing the link between the two species, an al...
Undertale Sister Scenarios by EmilySkelewolf
Undertale Sister Scenariosby Lady of WIP
"Like Underfell, but a different AU."
(Sans x Reader) When Two Souls Meet by ZanaBSparrows
(Sans x Reader) When Two Souls Meetby Zana B Sparrows
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...
Becoming A Undertale Multiverse by Caitlyn_Henry_Chan
Becoming A Undertale Multiverseby Aftertale Author~Chan
??? was a fan of undertale heavily but when she suddenly got hit with a truck (because everyone dies from trucks when they get isekaied.)she was expecting to be dead so...
Reset {UNDERTALE} by emotistic-optimistic
Reset {UNDERTALE}by Emotistic Optimistic
*FEATURED STORY* As Judge for King Asgore Dreemurr, Sans has seen a lot of strange stuff. But when he wakes up with the feeling that something is completely wrong, he de...