Underswap Stories

Mainly what the title says. Lots of Sans, ton of SANS, Undertale sans, undefell sans, ALL THE SANS. BUT WITH A CHUBBY READER. WHHHAAAAT I KNOOOOW. READ FOR THE FLUFF...

(I DO NOT WRITE ABOUT UNDERTALE ANYMORE SO PLEASE DON'T REQUEST ON MY CHAPTERS) (AND FOR THE LOVE OF GOD STOP COMMENTING ABOUT MY GRAMMAR, I AM SWEDISH AND I HAD A HARD...

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...

(As far as I know, no one has made a story about naturetale like this so..and the only reason why I writing one like this is because of fatal error part 5? Or part 4, go...

Yeah sorry gained an idea on if someone became swap Gaster Also they may be apathetic or just confused on their feelings and MAYBE Autistic, I may be a bit wrong on ap...

"There IS worse fate than death" The cover isn't mine. Just a few warnings: -boyxboy -girlxgirl(maybe?) -blood -su¡cide(kinda) -death

[Undertale Au's x F!Reader] Can be found in my Quotev Account --> @.FanboilingTrash | AO3 --> @.FanboilingWriter | Tumblr --> @.bdudette When Blueberry and Str...

UF!Sans lives in this hellhole, which is his life. "It is kill or be killed" and he learns that every day anew from his boss. But what happens when a broken s...

Note to self: Never make jokes about getting reincarnated into a video game character because it'll actually happen. Welp too late to go back now, considering I'm alread...

You were a kind human who has a brother named Frisk. You and Frisk always get along until both of you climbed up a mountain. very curious if the legend was true or not...

Blue is sick of being treated like a child by his friends and family. He shoves down his negativity in order to stay 'happy' like they want though. Nightmare has had eno...

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...

What if someone from our world became error and didn't destroy au's and left that for nightmare and his gang and claims au's? ( different things including personalities

Yes, here it is the fifth book! I went ahead and decided to make the fifth one now, new book, new ideas! Anyway, request are open, but give me some time to catch up wit...

being pulled away from your home while your simply enjoying some alone time can be annoying and to make it worse you have no say in the matter as 2 teams keep throwing...

Nightmare found a young child a long time ago. When they fell into a coma it sent him over the edge. several hundred years later the child wakes up in a castle of darkne...

If you can't tell what this is from the title idk what to tell you... I will do requests and they can be as detailed or as vague as you want. I will do OCs if you want. ...

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...

What if someone is reborn as Error? What if they aren't so bad? What if they're suffering in silence and keeping their job a secret for fear of hate? How will Ink react...

Y/n L/n. A special human with a special SOUL. Yes, her Soul Trait is something new. But other than her SOUL trait she has another secret. One day, while she was at the...