Gasterblasters Stories

This is a GasterBlaster!Underswap!Sans fic in the world of Underswap. Sans (or Blueberry) is a ten-year-old skeleton who isn't allowed to leave home. While his father (G...

In a world where heroes rise and darkness lurks, a unique girl named Sans finds herself thrust into the vibrant halls of U.A. Academy. With a mysterious past and the pow...

Sans and Papyrus' dad is the one and only Dr. WD Gaster. There mom is.. a werewolf?

Everyone thought all the monsters were sealed Underground, but upon making it to the Surface, a couple monsters nobody has ever seen before starts to make an appearance.

Basically what it says in the description... Just some pictures of Feraltale and BB Trust Au. Also some other pictures such as Temmie, Doomfanger, and The Annoying Dog...

⚠️Read first chapter for rules when requesting!⚠️ (requests will NOT be open again in the future) -*_This book is discontinued (Please don't read it, it's so bad.) _*- •...

Before the events of Undertale. . . All was well in the underground. A skeleton named Papyrus was training to be in the Royal Guard and his skeleton brother Sans was par...

Y/N is an Ultima but she is also a soul mix. A soul mix is when two soul types combine and become one being. She is a mix of CHAOS and CORRUPTION. The strongest soul typ...

You were only 13 when it happened, you were with your mom in the car when you were hit on the highway by a drunk truck driver. Since then you've seen some things others...

I'm writing a fanfic on the back story of Sans and Papyrus. P.S most of this is based on pure theory

Reincarnated in the BNHA universe with the powers of Glitchtale Gaster (By Camila Cuevas on YouTube, subscribe) and Nephilim Sans from the thought.

The life and updates on the gaster blaster-human meta crisis

no dire nada asta que la leas

Frisk is struggling four years after the monsters moved to the surface world... Chara seems to be trying to take over, and Sans can't take it. Papyrus and Toriel seek th...

(UNDERTALE Fanfiction Prequel) Gaster's tragic history as the underground's royal scientist, and the project that ultimately scattered him through time and space.

(DISCONTINUED. GO TO THE ACTUAL AO3 WEBSITE TO READ OTHER CHAPTERS) https://archiveofourown.org/works/5350673 It's over. Frisk's journey has ended in the best way possi...

Grace is an artificial monster on the run from her human creater and finds herself in the Underground. Follow her as she makes her journey through the underground

[[UNDERTALE SPOILERS!!]] After frisk had done the pacifist run many times, something gone wrong... Flowey never showed up in the end. So frisk lived in the underground w...

Erin was a gaster blaster who was made by dr Gaster for his son Sans. After a few years Sans had grown up and had left the lab taking Erin with him, he had other gaster...