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?

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...

(Cover Done By Me) Y/N is a very successful woman, who is the top surgeon in her job and has a family loan that is given to her every month. But even with her riches and...

Underfell is a dark world with the major rule of kill or be killed. Even though children are suppose to be secluded from this rule, that doesn't stop monsters from hurti...

trigger warnings will be placed at the beginning of each chapter! this story will contain mature content, be warned before reading.

I found this pictures on deviantart,pinterest,google and Frans Amino

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...

Remaster on my page - check it out! Sans has had an interesting past. A past that even his beloved brother barely even knows of. A past that he wishes could remain a sec...

(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...

It has been 10 years since the monster broke free from the barrier, and since then monsters and humans live together in peace. But for some reason, monsters have somehow...

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

Warning this contains suicidal thoughts. If you're sensitive to that sorta stuff I don't recommend reading this.

this is a story about a girl who finds little bitties who were abandoned and takes them in little does she know that its harder than she thought and that the bittys won'...

Geno is a lonely thief, resident of a small sea village. His past is covered in darkness. Somehow he can't recall who he was or his parents. He only had his 2 younger br...

(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...

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...

You were always put in second place due to your sister being favored over you. No matter what you did it always seemed that you both were competing against each other. Y...

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'...

You're the Ink of your multiverse, and you don't even know it. Well, until you meet the Ink of another, along with Error. -NOTES- I made the cover! This obviously isn't...

Nightmare is a simp for Error thats all ya need to know.. love at first sight? slowly falls into simpness? Will Error like him back? maybe..idk..read to find out Also...