1 - 20 of 291 Works in Alternate Universe - Fellswap (Undertale)
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Summary
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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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- Language:
- English
- Words:
- 3,337
- Chapters:
- 1/?
- Kudos:
- 7
- Hits:
- 70
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Summary
I'm bad at summaries... you work at a call center and get a repeat caller Black. Trust me it's better than my summary. 😅 will add tags as I go. So far only two skeletons.
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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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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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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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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
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You honestly can't remember when you had officially moved into the lodge to be with your datemate. It started as leaving things in his room under the (flimsy) excuse of having stuff for the next time you have an impromptu sleepover—but it was a not-so-subtle takeover.
The others didn't mind it either and were gracious enough to provide you with your own room for when everyone's shenanigans prove to be too much for you, but little did they know that they practically invited the devil herself into their home, because you're the queen of starting some bullshit or doing things for the bit.
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So I've seen someone else do this and asked myself, why not? I have loads of ideas/situations for fanfics yet have no time to write them or I end up just procrastinating for two years after posting the first chapter (if you're looking at my other fanfic no you aren't). So here goes nothing I guess.
Some will be longer than others, some I might expand on and make multiple chapters, but I don't think I'll make them into full fanfics. Some will have more oc's or more lore/backstory and some won't have any. Some will be about specific skeletons, others will be about all of them. There will be different tropes, jobs and personalities for Reader, and I might make them into a bit of a self-insert sometimes.
Again, if anyone likes any of these, please feel free to use them! But do tell me, mostly to read the end result ;)
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Summary
Names, and who's who.
Will be updated if/as new people are mentioned and added.
Series
- Part 1 of Time
- Language:
- English
- Words:
- 48
- Chapters:
- 6/6
- Hits:
- 44
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Summary
The skeleton family's plan wasn't to be hunted down and murdered by two crazy neighbors they'd never met.
Luckily for them, there was a reset, And they end up coming back the day they move into the house next to their crazy neighbors..
But they hadn't expected one of the neighbors to be so attractive under the mask.
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Continuation of "Pretty Like A Car Crash"
Crumble must prove to the facility that she can handle whatever is thrown at her, except sometimes the problems come from the skeletons that are supposed to help her.
It's up to her to prove everyone wrong.
Series
- Part 2 of Crumble and her Crumbling Life
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So I literally never see anything with a diabetic main character and especially not a diabetic /Reader fic. Skeletons are sexy so lets play around with ideas while I get a diabetic reader a harem of their own!
(I have been diabetic over 20 years and I honestly can't tell if I should be annoyed or amused at my own title)Series
- Part 1 of Diabetic Reader
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An ill-thought through party in the woods leads to you getting lost with a dead phone and no way to know where you're going. When all seems lost you stumble across a cabin hidden in the dark depths of the surrounding trees. In classic horror movie hero fashion you find yourself entering the creepy house to find more than you bargained for; including quite a few skeletons unearthed from the closet.
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On the day of their 13th birthday everyone has a name appear somewhere on their body. A script different than their own, but still familiar and comforting nonetheless. It's said to be your soulmates handwriting and, when you make physical contact for the first time, it's to change to the color of their eyes. Or so the rumor goes. But everyone knows that's just an old wives tale since finding yours is so far and few between.
But then there's you. What the hell are you supposed to do with 12 soulmates?? At least your odds are better than most...
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Making A Monster by absurdmagewrites
Fandoms: Undertale (Video Game), Underfell-fandom, Underswap-Fandom, Swapfell-Fandom, Fellswap-Fandom, Fellswap Gold-Fandom, Horrortale-fandom, Crafttale-Fandom, Seaswap-Fandom
16 Nov 2025
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Sometimes life throws you a curveball. For you, your curveball was going to bed looking like a human, and waking up looking like a monster.
A skeleton monster to be precise.
With the barrier breaking, a large surge of magic descended on the town you live in, and transformed you overnight. Unsure what to do with you, and the others changed, you're ushered into a facility until a monster with similar magic can take you to teach you how to wield the now uncontrollable magic you've been given. After waiting in this place for four years, you'd given up hope that anyone would ever want to take you.
What a surprise for you when you find out that someone does. A lot of someones.
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After playing undertale late at night and being sucked through your computer to that universe, you and your bone brigade have to figure out what it's like to live in a new world. And maybe try to get you home. If there's time.
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Here we are again! Another series of Undertale one-shots following the Fictober prompts and featuring the skeleton brothers as love interests to either my nameless or named girlies.
Just like the past two years, if you'd like any of these to be turned into fics, then please let me know in the comments! If enough people show they're interested, then it'll be added to my list of future fanfics! Five requests are what's needed for them to be added.
And if you choose to wait till the end of the month to read, that's okay! Requests can be made up until November 7th, when I post the list of the lucky winners!
Hope you all enjoy!
Series
- Part 3 of Fictober
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AO3 description: Long ago, two races ruled over Earth: Humans and Monsters.
One day, war broke out between the two races
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And that war won’t rest for you.
(Fellswap Gold story with some elements from Canon/Classic Underfell. Content for routes outside of the Closure Route [see: Underfell’s new routes, Closure is Pacifist] is unlikely.)Series
- Part 2 of Fizzyverse [UNDERTALE]