1 - 20 of 3,054 Works in Underfell Sans (Undertale)
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The first stranger looked like Sans, but his jacket was the wrong color and his smile was too sharp. The second looked like Papyrus, but he was far too rough and terrifying. Now, Grillby’s is filling up with shadows of the people you know best, and your own Sans and Papyrus won’t give you any help in the mystery.
As your health begins to fail in ways no doctor can explain, you’re left with one question: Why are they all here, and why does it feel like your life is the price for their arrival?
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You're on the way to your new apartment, new job, new life, but you can't keep your eyes open.
You stop at the first motel you find, and discover it's full of spooky skeletons!
A lot of skeletons. -
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Summary
You only wanted a normal life.
But somehow, you ended up meeting them.
And nothing stays simple after that.
Arc 1: (Familiar Warmth) Chapter 1-18
Arc 2: (What Survived) Chapter 19-20
Arc 3: (True Beginning) Chapter 21-60 (Subject to Change) -
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The first story of the series. Follows our protagonist through his rebirth and until he (re)enters the Multiverse.
The Major Character Death Warning is temporary and happens multiple times btw, it is a little confusing at first but you will understand as the story continues.Prologue: Rootverse's Collapse (1)
Arc 1: Rebirth (2-7)
Arc 2: Meeting Familiar Faces (8-80)
- Sub Arc 2.1: The Teeth Incident (20-41)
- Sub Arc 2.2: The Magic Incident (42-50)
- Sub Arc 2.3: Time For Shopping (51-59)
- Intermission: 1st Major Time Skip (60-62)
- Sub Arc 2.4: The First Human (63-80)
Arc 3: The Tragedies That Follow (81-?)
- Intermission: 2nd Major Time Skip (90)
- Sub Arc 3.1: The Six Souls (91-?)Series
- Part 1 of Miseries of Metempsychosis
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Undertale / UTMV sanscest hypnosis oneshots by Chris_ghosty77
Fandoms: Undertale (Video Game)
11 Jun 2026
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Summary
My first work, a book of oneshots focused on hypnosis / mind control.
Most stories will be non/dub-con so be careful.
Almost any ships, focused on sanscest.
Edit: The number of tags being limited, please read the summary of each chapter to know the warnings / kinks. I hope you enjoy reading this book as much as I love writing it.Series
- Part 1 of Undertail hypnosis series
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You and Sans had been working on this machine, and suddenly it works!
But now there are a bunch of skeletons appearing everywhere and you can't stop it.Well, you guess they're kinda... anyway!!
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Reverse harem with Sans and Papyrus aus. I plan for it to be a slow burn but it's my first time writing it soo....
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((- A Flowerfell/Underfell Sans x Reader.))
Your love bloomed for him.
As your flowers bloomed through your heart.How could someone so heartless himself.
Ever fall for such a sweet soul.You truly were, his sweetheart.
Floret meaning: One of the small flowers making up a composite flower head.
||Original On Wattpad|| -
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A rewrite of a previous fic, changed structure and story and more Sans' to have sex with.
Years have passed since the barrier had fallen and freed the monsters. You had your found family with them, Sans in particular being your best friend and support. You heard of SOULmates and how monsters have them, you wondered yourself if humans also had SOULmates, and you find out as you begin to travel through different Undertale AU's just how SOULmates and SOULs work through the multiverse.
*I DON'T USE Y/N*
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Sci is off work for the weekend! You know what that means: absolutely nothing fancy at all.
Series
- Part 30 of Scifell
- Language:
- English
- Words:
- 1,165
- Chapters:
- 1/1
- Hits:
- 13
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Cross and Chara have been stuck in their dead au for a while. Ink didn't come when he was suppose to. Their lack of cooperation has gotten worse. Chara continues to let out his anger on Cross and Cross has given up hope of escaping. When they have an epic fight ending with both of them hurt and alone, they can think. They both made mistakes, suffered, and want the same thing-Xtale's ressuraction. They are all each other have and need to get along or atleast work together. When Ink starts showing up, they have the chance to escape into the multiverse and earn their happy ending.
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When the quiet solitude of your new life is disrupted by a gaggle of skeletons moving in next door, you and your sibling find yourselves pulled into their orbit. Healing takes time, but maybe, this chaotic, affectionate family is exactly what your soul has been waiting for.
*Inspiration taken from "Bonely Hearts Club" fangame by owl-bones (http://bonelyheartsclub.tumblr.com)*
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“Fuck you and fuck your mom and fuck your recovery,” the other sans snaps, coming to a halt only a few paces away with his face twisted towards Sans where he’s perched at the foot of the bed.
His eyelights are practically pulsating, molten hot pink with rage. Nonsensically, Sans registers that it’s a really pretty color. “Were you even listening to me, you little nutjob? I killed Gaster to protect my brother. Now riddle me this, asshole: why would your brother, the laziest fuck in the Underground, plot and execute a whole entire murder with a girl he barely knows?”
(Act Two, or: Blue goes on a road trip across time and space to salvage what’s left of Edge.
the direct sequel to ‘little blue pills’ and dealing with the events in ‘everyone learns faster on fire’
Off hiatus as of 2026)
Series
- Part 3 of goddamn, we missed the vein
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(Set in Aggreg(g/v)ation by Llama_goddess and based off a very specific ask)
A month ago, Hit showed up to your door. No, he didn’t come back through the machine… he was a baby. Red eyelights, baby shark teeth, and a small crack on his face.
It was a little adventure getting everyone used to having the little baby menace in their home. Skull most of all, taking the longest to separate kidnapper and baby. But eventually, the four of you became perfect caretakers for the infant.
… This afternoon, whatever magic was done to him had reversed, and an adult Hit with memories of what he’s done stood in the middle of the living room.
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The Story Was Supposed To End. by TheRogers_Archive
Fandoms: Underfell - Fandom, Undertale (Video Game), Undertale AU - Fandom
10 Jun 2026
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"You're just a character."
That was the truth when you were fourteen years old, curled up in your bedroom and reading stories late into the night.
Characters belonged on screens. In games. In comics. In worlds separated from your own by lights and pixels.
But one day, that distance is gone.
The story has bled into reality. The line between reader and character has vanished, and the ending you thought you knew no longer exists.
You aren't reading the story anymore.
You're trapped inside it.
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You awaken in a space between worlds with an entity who seems concerned for your wellbeing. After they place you into a new home, your life gets to develop in strange ways within a strange world. However, you weren't sure how long this peace will last.
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Nightmare knew he was not the best in the Multiverse.
Hell, he was not even good.
He was the God of Negativity, a title that followed him like a curse carved into his very bones, and it made perfect sense that someone like him would end up completely alone.
Or: Nightmare is lonely so he ends up recruiting Killer, Dust and Horror all based on misunderstandings.
With fanart!
Series
- Part 3 of Undertale AU's
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✨
He skidded to an unsteady halt as he finally got a close look at the two passed out Skeletons.“What the fuck?”
Blue didn’t swear often, but this? This definitely merited it.
✨Error and Ink are caught in a …little… accident and now everyone else is left to deal with the aftermath.
{{I try and Update Every Sunday :>}}
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A Shattered Ruby by KTamao205
Fandoms: Harry Potter - J. K. Rowling, Undertale (Video Game)
06 Jun 2026
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Sans and Papyrus were just trying to have dinner.
They didn't expect things to blow up (literally).
Now they have a destroyed machine and a young babybone that they suspect as a Shifter. Where did they come from? And who's life privilege they need to remove? Because this babybone is clearly been abused or worse. Now then, where's that parenting books Sans been storing since Papyrus a babybones, he's definitely need a review if they want to keep the kid from getting killed.
At least the kid's adorable...
Series
- Part 2 of Arcalith
- Part 2 of MultiTaleVerse
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"A Flower's Blood" is a SENSATIONAL MMORPG that Cross's little brother, Chara is OBSESSED with! Chara even forces Cross and Frisk to fight monsters with him. God, Cross really doesn't have time for that...
But after beating a boss with Chara and Frisk, Cross is about to turn off his PC and go to sleep when the number 1 player that kills every other player that gets too close suddenly send him a friend invite.
The next day, every player is now in the game and Cross has to find DarkNight.
(I can't find a tag for it but Nightmare is fem in this)
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Living with two annoying skeletons has its ups and downs.
We're showing the ups here.Oh, and also how they go down on eachother.
Series
- Part 2 of Three idiots