Underfell Stories

1.2K Stories

(Underfell sans x reader (female)) UNDERCOVER by moon1767
(Underfell sans x reader (female))...by Arie
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?
Power to Heal (Underfell!Sans X Reader) by Fruityyloopz
Power to Heal (Underfell!Sans X Re...by Justmonika
You wanted to help but it was too late... So, you left. Tears filled your eyes as you thought of the one person that needed you the most... They were gone and it's your...
You and Your Bitty Pals by Blueprint15778
You and Your Bitty Palsby Blueprint15778
It has been 5 years since monster broke free from the barrier, since then monsters, and humans live together in peace. But for some reason monsters have some how go a mi...
Furtastic by Lunawolf34
Furtasticby J. E. Collins
A girl who has never seen the world outside of the lab sees it for the first time only to fall down into the underground. What will she find down there?
The Glich of Multiverse  by PuppetMariMarionnete
The Glich of Multiverse by M
Error is a glich , there is no question about that and because of that he is also verry powerfull to the point he can destroy a AU with one move . He was modified by cr...
Castle's Pet (Bad Guys X Reader) by EmelinStriker
Castle's Pet (Bad Guys X Reader)by Emelin
[Highest Rank: #1 in "sans"] [Second Highest Rank: #18 in "xreader"] (Girls only!) (Earlier updates are on my Quotev account!) WARNING: Profanity a...
Undertale: giving soul by Author-Dayo
Undertale: giving soulby Author-Dayo
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...
'Shy Pet' Underfell Sans X Reader by sentifrost
'Shy Pet' Underfell Sans X Readerby noé
[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...
|| Catching Feelings || AU Sanses x Reader! || by sydneysayshello
|| Catching Feelings || AU Sanses...by im going to cough on you
You kind of zoned out for a bit, trying to piece together what they said, when the door opened suddenly. You let out a small shriek as your head slipped and you hit the...
Healing *Discontinued For Now* by Dyell_Does_Writing
Healing *Discontinued For Now*by Dyell
Sans (Red) is a monster trapped in the nightmare that is Underfell. Brotherly abuse and the stresses of this world cause him to do the unthinkable, how will the Swap bro...
Bitty Life by UnslurRat
Bitty Lifeby Koii(He/They/It)
I was dragged in by my friend, Aliza, to get one.im not a pushy type.so I went to the websites. now, what's this?!
Can I take you to Dinner? Mafi-fell!Sans x Reader.  [COMPLETED] by MissHoll-E-Socks
Can I take you to Dinner? Mafi-fel...by MissHoll-E-Socks
"How rude, not even gonna ask for a name??" He teased. "Why are you here?" You glowered, raising the whisk. The skeleton scoffed: "Well, glad yo...
My Two Masters (UF!Papyrus x Skeleton!Reader) by OreoDaSkeleton
My Two Masters (UF!Papyrus x Skele...by OreoDaSkeleton
Y/N's been traded and sold her entire life. She's learned firsthand that if you don't obey your master, you get hurt. If you force yourself to listen, you live another d...
You have become an Error (Discounted For Rewrite) by MikkiMausu
You have become an Error (Discount...by MikkiMausu
(Discounted for a rewrite) A shy girl dies in her reality saving a kid from a speeding car founds herself trap in the anti void as a being called Error Sans the god of d...
Just Strumming Along || {Reader x AU! Sans ((and some Papyrus's!)) } by galaxcoffee
Just Strumming Along || {Reader x...by ✨☕️
When (Y/N)'s grandma passes away, she moves in her grandma's beach house in Oahu with her ukulele. But what happens when she plays that ukulele by the sea and a "po...
UnderFell Sans x Male Reader  by HappyHuman020
UnderFell Sans x Male Reader by ~~Mirka~~
I have seen alot Female Reader's x Fell sans So i wanted to try a Male Reader! :) Please be aware that i am not good at this types of books. :) ⚠️ THIS BOOK CONTAINS ⚠️ ...
I am the classic by KarmaAkabane425
I am the classicby Karma Akabane
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'...
"just to see you smile" ( AU sans x emotionless reader) by newttheyandere287
"just to see you smile" ( AU sans...by bbgirl.eats.shickennuggets
(y/n) is a maid for a huge mansion living in the servant's courters. Through her past of pain, and trauma has caused her to lose her willingness for emotion only able to...
{Human! Underfell! Sans x Reader Smut!}  by H0ney_Bee
{Human! Underfell! Sans x Reader S...by ✩𝔻𝕒𝕕𝕕𝕪✩
Snowdin's most hated douchebag has finally noticed your existence. Now, you really wish he hadn't- This was a request, so please be prepared, I hope you enjoy this-!
Simpmare  [Errormare] by DahRadSkeleDude
Simpmare [Errormare]by JJ_loves_Ruru
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...