1 - 20 of 4,392 Works in Alternate Universe - Underfell (Undertale)
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Doomsday prep has always been necessary in my opinion. If not for your time, then for another's time. So I got married young, to a much older, much richer man, waited a few years for him to die (cancer, so sad), and collected that money like candy at a parade. Then I picked out a nice place for a bunker, and had that thing built in another few years. When Monsters busted out of the mountain nearby, turning some Humans into Monsters, I was only slightly surprised the government's decision was to fucking nuke them all. Now I'm closing the door, and I see people in the distance waving their arms, yelling. I should just close the door, I don't know them, but I don't think it's fair to leave them out to die.
Author's notes, kinda:
Gonna be just Horror, Fell, and Fell/Swap variants.
Characters like Sans, Toriel, Asgore, Frisk, and others are really only mentioned, except Horror Sans.
Papyrus variants are more like different people in this, than variants of the same person.
Also, I don't really like Swapfell Pap (Purple) so sorry, but he might only be there for drama, not for a relationship -
These Skeletons Need an Emotional Support Human by Crooked4913
Fandoms: Undertale (Video Game)
14 Dec 2025
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You were a human who had made mistakes in your life, but then again who hadn't. Your mistakes however led to you barely scraping by, pinching every penny to afford food and rent.
Until a chance encounter with a skeleton in a grocery store gives you the opportunity of a lifetime. He says his roommates fight over everything; Cooking, cleaning, shopping, yardwork, ect.
So, what if they hired you to do all those things? That would stop all the fighting, right?
You can't turn it down for the kind of money that there offering to pay you.
besides, it isn't like monsters are actually dangerous right? -
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You and your family are just enjoying a nice day at the park, when a life changing event happens that ruins everything.
You get taken away to a facility to be tested on...
Life doesn't feel as peaceful as it once did, you hated your new life.
"I wish I could just go into those story books I used to read..."
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"I'd Rather Do Normal "People" Things...Thanks!" by Cr8ter_Eight
Fandoms: Undertale (Video Game)
14 Dec 2025
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You are a Normal Person in pretty boring world.
You wake up.
Brush your teeth.
Comb your hair.
The same repetitive, insigniFi6@^t- th!^g every $ingle day....
One day, you do the same thing.
On that same day, you don't notice that an Insanely huge skeleton has tumbled out of your closet.Amazing.
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The Skeleton brothers find a new... companion. He's a lot of work, but it's worth it.
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Post pacifist route Undertale but they stayed underground. Frisk’s memory was wiped and no one remembers them. Asgore and Toriel are adults and everyone else is a teenager and they all go to high school together. Frisk is still adopted by the Dreemurrs and Asriel is back!
- Language:
- English
- Words:
- 1,219
- Chapters:
- 1/?
- Kudos:
- 1
- Hits:
- 49
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You wake up in an empty room, you can't remember who you are or how you end up here, all you know is that you need to leave this place. Your first encounter being a pair of skeleton brothers that seem both too nice and scary, you wonder what's the deal with this place but does it really matter? the place is full of strange creatures, what would you do?
There's no place for someone like you in a place like this.
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Papyrus and his Detective partner (you) have to solve a missing persons case. It turns into a huge undercover operation where you still have to rescue the missing person: Sans!
Along the way there's shenanigans, swearing, sex, misunderstandings, bad puns, and you fall in love with your spiky partner's brother. -
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make no mistake, that's what he heard. Frisk had fallen down into a hostile world, what appeared to be out to get him. then there was a human, one who hated her species with a burning passion. but will an encounter of the two change that? and what else will happen with Frisk's adventures?
Series
- Part 1 of My Undertale AU Stuff
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Sometime in early October, a few years after monsters have come to the surface you move in with your friend, and used to be coworker, Sans. You’ve been through quite a bit together but even still there are secrets you won’t share. It’s only a matter of time till those feeling bubble to the surface.
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You ended it all one fateful night, but instead of dying, were swept up in a world of war with a bundle of a skeleton in your arms. With a crazy scientists chasing you for something you don’t even remember doing, figuring out how to escape with your little brother still alive, a life that isn’t quite yours, lots of angst, and even more comfort… this will be quite the wild ride.
Now including a skeleton-house that is becoming VERY concerned for your mental wellbeing, (buried after the much-needed war-trauma,) you have to deal with a whole ‘nother group of wacky skeletons judging you. AGAIN.But… in order to have the best comfort fic, you sometimes need to have the worst angst beforehand.
Or, as Gaster once said… you need to break a few eggs in order to make an omelette. :]
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(Please) be reasonable by Otaku_girl for HasBeenHellWolf (FelliSkelli)
Fandoms: Undertale (Video Game)
12 Dec 2025
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“Boss, please… c’mon, can’t we be reasonable about this?”
“I hear that you are out there, acting like a complete hussy on top of everything else! Just what do you have to say for yourself?”
“Boss, please. You could… you could remind everyone of who I belong to.”
“Oh, I’ll make sure nobody can forget who you belong to. Nyah-hah-hah.”Sans’s smart mouth gets him in trouble. Papyrus teaches him a lesson.
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After going through favoritism your whole life, your father forces you to get married to a neighboring kingdoms king, too bad he doesn't want anything to do with you
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Sans did not remember his previous name, only that he had been human. Rebirth in Undertale was novel, but he adapted, until he realized that the universe he was in was not the original one.
Unfortunately, it was too late when the machine took him to another universe, into a room full of skeletons.
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Sans no recordaba su nombre anterior, solo haber sido un humano. Renacer en Undertale fue una novedad, pero se adaptó, hasta que cayó en cuenta de que el universo en el que estaba no era el original.Lamentablemente, ya era tarde cuando la máquina lo llevo a otro universo en un cuarto lleno de esqueletos.
Nota: Sé que suena como tragedia, pero en realidad es una historia bastante esponjosa de curación, o al menos eso intento. Nuestro protagonista tiene mucho trauma y lo va a sanar en una mansión llena de esqueletos incómodos
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It's been four months since the whole world tilted and spun out under Sans, dropping him into the snow in front of a very tall skeleton.
Four months, as it turns out, is a very long time.
Series
- Part 2 of no way off the hamster wheel
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What if you're finally free? On the surface with all your dear friends? But then an incident...
What if a reset happens?
I'm back with another what if for my first fic (a new life with a bunch of monsters (and annoying humans))
God i need to stop😭Series
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After the events of Multiverse Madness, with Shattered and Reality now back in their own multiverse, the fighting is quick to once again break out. Reality explores and learns about his multiverse and the damage Shattered has done to it and attempts to save it, while Shattered continues his efforts to stop Reality and get him encased in stone again. The two of them make allies and enemies, Reality making friends and becoming part of a found family while Shattered follows in Nightmare's footsteps and manipulates his allies into thinking he cares for them. Traumas are experienced, friendships are strained, loyalties are tested, and deaths are witnessed and grieved for. It's an emotional rollercoaster, so be prepared for what happens, as it's not for the faint of heart.
Discord server: https://discord.gg/wQfvxyEuvj
Tumblr in case you guys want to make fanart: https://www.tumblr.com/werecat1234
Shoutout to my beta readers Ali, Rain, Iluvdragons, Prophet, Poki, Clichély, Nova, and Note of Joy! You guys are awesome! Thank you guys so much for beta reading this for me and giving me feedback on the story, you have no idea how much it truly does help!
Series
- Part 4 of Werecat's UTAU Megaverse
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Unavoidable Outcomes by Crystalight532
Fandoms: Undertale (Video Game), Undertale Yellow (Master Sword Video Game)
11 Dec 2025
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The Multiverse isn't as unreachable as one might think. Sometimes, all it takes is one aware person to tip the scales for another to find out about it. But when one isn't ready for it, returning to their own world is relieving and best for the psyche.
Humanity's thirst for knowledge is near insatiable. How far would they be willing to go to learn more about their new magical coinhabitants on the surface? How far would they go if they could weaponise their magic?
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Wake up buried in snow, alone, and with no memories?
Check.Keep seeing numbers, words, and random text floating around every object and surface as far as the eye can see?
Also check.Why does every person he meets say he needs help?!
He’s perfectly fine, if you ask him.“I wonder what determination tastes like.”
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Note from the author:
This is my take on Fatal Error — a much more non-canon,[this isn’t even OOC, this is just straight-up a different person with the same name]
amnesiac version of him.
He’s also not fully canon-compliant in terms of power scaling and may even have a different origin and and backstory.It’s my reimagining of him with a completly diffrent story.
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Stretch has been your best friend since you two were children. Ever since you first introduced yourself to him, he's felt this pull towards you, and you can feel it too. The two of you have been harboring crushes for so long, will either of you ever confess?
Blue didn't really know what the machine in the basement did, it was his late father's old project. When drunken mistake causes this dormant machine to suddenly spit out skeletons who look eerily similar to him and his little brother, how will they deal with their counterparts in a foreign world?
Act 1: Flowers Waiting to Bloom (Chapter 1-20)
Act 2: Fields of Flowers (Chapter 21 - 38)
Act 3: Petals in the Wind (Chapter 39 - 45)Series
- Part 1 of Forget Me Not