Gaster Stories

Monsters weren't always living peacefully with one another underground and the humans didn't always have such a vendetta against them. There used to be a hierarchy that...

What if our favorite knuklehead ninja goes to Undertale multiverse, become a monster, and has gamer system? This is my first story.

When the young, emotionless,and former bodyguard of willy tybur ends up on the wizard council and meets the royal scientist known as W.d gaster and feels feelings she's...

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...

What if GT!Gaster had a siblings, in the alternate timeline, this timeline GT!Gaster has a siblings, the name will be revealed in the story soon! :D

You and your sibling, Frisk, have been living in a forest near the city for about four years now. Your daily routine has been unwavering since you moved here. Each day...

(Currently rewriting since this has too many plot holes) The reader gets stabby stab, gets sent to the void then- This is for shits and giggles, I didn't even plan the w...

A few years had went by since you made your home in the Underground. You had started a family, started a life. You had a kid and a job at the Arcade. But finally, Chara...

(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...

A young woman dies and is reincarnated in an Undertal Au she made as one of the Skeleton twins. Will she change the multiverse? She changes things in her AU for good or...

Fluff Smut "Oh shit that's a (opposite gender)!" Moments And, of course, my and Gaster's virgin asses

It's a beautiful day today. The birds are singing and the flowers are blooming. But out of nowhere, Sans, his brother, and his three friends are asked to take care of t...

What if when Gaster fell into the C.O.R.E, instead of ending up in the Void, he was transported to a different universe were magic doesn't exist and he is turned into a...

I decided to do an ask & dare with my AU, Staintale. Staintale is a AU where Frisk and Chara are controlled by the player, Chara, Frisk, Flowey, and Sans all remember re...

In a timeline where Eliza had yet to fall, (Y/n) had fallen instead. This was the world of the 'Eat or be Eaten' and (Y/n) did not belong here. Definitely did not belong...

After Chara decides to humor Frisk, things don't go entirely as planned.

Everyone is finally on the surface. Humans and monsters have made peace. Harmony has finally been reached. No issues or problems with anyone exist anymore... Right? Well...

This Story is taking place after the phase 3 event of Sans, finally losing against the human. Sans wakes up in a mansion and meeting with a blonde yellow with ponytail h...

[👎︎✌︎☼︎😐︎ 👎︎✌︎☼︎😐︎☜︎☼︎ ✡︎☜︎❄︎ 👎︎✌︎☼︎😐︎☜︎☼︎] After you and Frisk freed monsters from the underground. You felt like your journey was finally over, that you helped f...

𝚃𝚑𝚒𝚜 𝚋𝚘𝚘𝚔 𝚠𝚒𝚕𝚕 𝚋𝚎 𝚏𝚒𝚕𝚕𝚎𝚍 𝚠𝚒𝚝𝚑 𝚐𝚕𝚒𝚝𝚌𝚑𝚝𝚊𝚕𝚎, 𝚄𝚗𝚍𝚎𝚛𝚝𝚊𝚕𝚎, 𝚗𝚎𝚟𝚎𝚛𝚝𝚊𝚕𝚎 𝚌𝚑𝚊𝚛𝚊𝚌𝚝𝚎𝚛𝚜, 𝚠𝚒𝚝𝚑 𝚋𝚒𝚝 𝚜𝚙𝚘𝚒𝚕𝚎𝚛𝚜...