Gaster Stories

1.2K Stories

Reborn as a baby Xtale Gaster by Cosmicstars08
#1
Reborn as a baby Xtale Gasterby Cosmicstars08
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...
To Hell and Back (Gaster x Reader) by xsfolia
#2
To Hell and Back (Gaster x Reader)by everail
"What's that look for? Are you perhaps unhappy to see me?" "Oh no. Oh no, quite the contrary, my love. I've craved to be with you for the longest time&quo...
Completed
Divided [ Sans X Reader ] by morrow-
#3
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...
Completed
The Ghost Above Me (Gaster x Reader) by xsfolia
#4
The Ghost Above Me (Gaster x Reade...by 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...
The Void Hero| Gaster x My hero academia  by Lost_Naito
#5
The Void Hero| Gaster x My hero ac...by Lost Naito
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...
The Skeletal Hero: Karmic Judge by A_Toast1
#6
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...
Completed
Child of the Void (Gaster! Reader x RWBY x Highschool DXD) by KyogreKing120
#7
Child of the Void (Gaster! Reader...by 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...
Undertale Scenarios by InWolfsClothing
#8
Undertale Scenariosby In Wolf's Clothing
A series of semi-realistic scenarios including a handful of Undertale characters. In otherwords, stick around. ... Please.
It's time to be a [BIG SHOT] in Remnant. by XpancakesBeconX
#9
It's time to be a [BIG SHOT] in Re...by XpancakesBeconX
(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...
A Bizarre Timeline - Glitchtale Fanfic by Suzunori_Sumire
#10
A Bizarre Timeline - Glitchtale Fa...by Suzunori Sumire
After all the chaos that occurs in Glitchtale, a mysterious traveler offered Chara a contract, which he reluctantly accepted. Turns out that person is a Creator, and she...
Completed
2 Sans and a Papyrus (Undertale story) by SpiritWolfNura
#11
2 Sans and a Papyrus (Undertale st...by Kyran Wolfe
W.D. Gaster never meant to fall in love during the war. But he did. It resulted in heartbreak, a pup, and a high LV. So he experimented. 10 years and no more kid. So he...
Completed
The Time Before (Undertale) by ANinnyMouse42
#12
The Time Before (Undertale)by ANinnyMouse42
~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...
We Speak In Hands (Gaster x Female!Reader) by OreoDaSkeleton
#13
We Speak In Hands (Gaster x Female...by ~Oreo~
Gaster is the current royal scientist, set with a mission to break the barrier and free monster-kind from their underground prison. His loyalty and persistence to the ta...
Gaster gang x child reader  by Niharafroon
#14
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 ?
Lazy, but still got a harem (To Love Ru x Male Sans Reader) by MylesDTate
#15
Lazy, but still got a harem (To Lo...by Galactics
(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...
(Sans x Reader) When Two Souls Meet by ZanaBSparrows
#16
(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...
Completed
Soul of a Weapon by SpiritWolfNura
#17
Soul of a Weaponby Kyran Wolfe
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...
Completed
Money, Jokes, and War (Sans x Reader) by awkward_casey
#18
Money, Jokes, and War (Sans x Read...by no<3
A young girl, Y/N, has one of the rarest soul types- -empathy. She can feel when people are having a bad day which leads her into meeting two skeletons. While one quickl...
No Chocolate - Chara X Frisk by phosphorus14
#19
No Chocolate - Chara X Friskby Phosphorus
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...
Completed
Undertale x male reader - Reborn  by kinder1000
#20
Undertale x male reader - Reborn by Kinder
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...