Underfell Stories

You're a human that has fallen into Mt. Ebott on the year where all humans dress as monsters...Halloween. So how will the monsters know if you're a human or not?

You were afraid. For the first time in your life, you were truly afraid. You weren't afraid of the never-ending darkness that had now consumed you. You weren't afraid of...

(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...

[Disclaimer that this book is very old nd poorly written, please keep that in mind!] You were shy. You were small. You were picked on. You were told you weren't tall eno...

A young human runs out of the ruins desperate to get to safety. She runs into the Skeleton brothers Sans and Papyrus. Before she can know what's happening her world is c...

*WRITTEN IN 2016* "Can someone please just tell me.... Why him.....?" Confidence. That emotion has been coming to you a lot ever since you had met him... But...

Sans and Papyrus were your best friends until randomly they just cut off all contact with you. This went for everyone else in your life so it didn't really hurt that muc...

What if someone died and was reborn in an undertale au as a siren? And not just any kind of siren, but a sans, a skeleton siren. They can change back between full skelet...

How would your life be as Sans and Papyrus's sister in Underfell?

Y/N is a half Demon Half Human, who lives with her friend Amy. They moved to a little town recently where Amy has loads of friends, which is the reason both of u moved...

(I want to point out RIGHT HERE that this is NOT a Reader-Insert. I'm just to preoccupied to fix the description here, and don't want to rewrite the official first chapt...

(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...

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...

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. ...

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

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...

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...

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'...

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...

(m / n) (L / n) is a 19 year old boy and he is frisk's cousin, (m / n) always looks after frisk like his own sibling because since childhood frisk has always been treate...