Underswap Stories

❝ Long Ago, Lived Monsters, Humans, Mages, and Dragons. All living in peace. Until humanity decided that Monsters, and dragons weren't meant to thrive in peace along wit...

Moved from AO3 because of reasons! "You are the only maid (or worker in general) that serves for the Skeletal Household. It's a skele-ton of work, but you manage by...

It was your normal, average day. You were staying at a friend's place while she was away on some adventure in Europe. Next thing you know, some uninvited guests show up...

Y/n was and/or is a very sweet child, unfortunately for them they weren't treated very well by their mother or father, Y/n was abused and didn't have anyone. Fortunately...

Bad Time Trio meets BNHA Disclaimer: I do not own BNHA, Or Undertale, or any of the AU or any of the pictures showed

Hi guys! First of all I should mention that the story pic isn't mine and of course Fellswap belongs to its original creator. A young hiker, Y/N gets lost and accidental...

What if someone died and became the tree of feelings from dreamtale? Well things won't stay the same, that's for sure. (Different everything etc, different personalities...

Sanses included will be...Classic, Swap, Fell, Swapfell, Ink, Error, Dream, Nightmare, Dust, Killer, Lust, Horror, and Fresh. Please be aware that the pronouns used for...

So harem book of Charas and Frisks x male reader but real description is below this. The only one of his person in all universes is part of Undertale with an OP powers b...

This is a story before the last human fell around the time Chara was still alive and well. Humans were not being hunted till the adopted prince's passing, however with a...

He knows he'll be dooming them if he falls, but he's tired, his body is breaking apart, held together on a higher being's whim only. He wonders if there'll be another to...

Who thought that one day someone would break into your house and slice your neck in your sleep? Well, that was what happened, right before you were integrated into a shi...

(Edit September 4 2023: requests closed as of like six years ago sorry guys) Read to discover which events take place in the Void as (Y/n) journeys throughout life with...

A passive soul from our world is reborn as a Sans who has to take action, Ink. As willing as a soul who was forcefully reborn they take charge of their baby of a multiv...

What if..someone from our world was reborn as fellswap sans? But an accident when he was young leads to becoming blind for a long time and papyrus feels guilty about not...

Somehow...I've become a sans...and not just any sans.. I'm classic!? What the flip is going on!? Wait why are different sans and papyrus's showing up at my home? I didn'...

What if someone became papyrus from underswap? What if they gave their brother more freedom? What if they were the one that error kidnapped instead of sans? (Things wil...

This story takes place after the player vanishes from their fight with the bad time trio aka Sans, Shift, Stretch. The three got stuck there for a very long time until a...

Completely female readers unless a request asks different. That's...really about it, enjoy!

Humanity is divided over one thing---the Monsters' reappearance. Some believe that they should stay aboveground, and others think that they should be sent back to where...