1 - 20 of 3,116 Works in Alternate Universe - Underswap (Undertale)
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Wake up buried in snow, alone, and with no memories?
Check.
Kepp seeingg numbers, words, and 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?!
His perfectly fine if you ask him."I wonder what determination taste like"
Note from the author:
This is my take on Fatal Error—a much more none canon, this isbt even OOC this is just straight up diffrent person with the same name, amnisiec version of him.
He’s also not fully canon-compliant in terms of power scaling and has and maybe different origin and personality.
It’s my reimagining of him.
Glitchy, lonely, and filled with questions, bad puns, power to blow up annoying people and some more puns. -
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The island had been forgotten for a long time now, the monsters believed that they would now live in peace on their island far from the human world. But humans are the most megalomaniac beings of all. Eager for riches, they began to plunder all over the island, and the monsters were unable to counter them. But what would happen if a scientist and a monster agreed to create new life forms, to stop all this?
Our skeletons will have DNA from dangerous animals inside them!
O and the island suffers from a shortage of females so... it will be fun🤭
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Papyrus has always loved his little brother. It was the fundamental point of their past and present relationship. Yet now it felt like a hollow love. The way you loved a small child you’ve never met, not the deep, close love of family. It’s been 9 years, so why now?
And suddenly Papyrus has had enough.
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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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You're a spy who is ordered to spy on the queen of monsters but two skeletons get in your way
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Two friends, just wanting to find an escape to their ruined world, try to use a machine that would supposedly fix everything.
They really didn't expect to wake up in a new multiverse.
They definitely did NOT expect to wake up as the Destroyer and Creator themselves.
Both just want to find their friend, for them to be ok.
The Multiverse has bigger plans for them, however.
Or: two kids make themselves spawn in the UTMV, but they have to fight each other to keep the balance.
Generally random updates but never more than a week.
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Undertale Alternate Universe Nicknames: All Main Characters by Creator_Kai
Fandoms: Undertale (Video Game), Deltarune (Video Game)
01 Oct 2025
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A compiled list of various Nicknames for Undertale Alternate Universe Characters. This is a FULL list created by myself for all the Characters throughout the Undertale Multiverse. It's not complete and likely never will be because of how many AU's exist, but there is quite literally no better list than this one if you are looking for Character Names to use in your UTMV stories.
Includes:
—Sans AU Nicknames
—Papyrus AU Nicknames
—Frisk AU Nicknames
—Chara AU Nicknames
—Toriel AU Nicknames
—Asgore AU Nicknames
—Undyne AU Nicknames
—Alphys AU Nicknames
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Here is a place where some of my other works, or Undertale short story blips, will make their way into the world. Some have the potential to become full stories if liked enough.
It is time some of these were shared.
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Red blares into your eyes as alarms scream, and wail into the air.
Their shrill shrieks mixing with your own wheezing breaths. Even as the helicopter sways precariously, the various vegetation its tangled in groaning and threatening to snap under the immense weight, you still can't find it in yourself to tear your eyes away from your pilot.
Or, rather, what remained of her.
The metal, having come flying off of Runner's copter and straight into yours, painting the cockpit in shades of red and grey, wasn't the only piece to crash through the windshield. But it was the one that did the most damage. Crashing through the window, and sending shards of glass directly into Strong's eyes, the metal had sliced... No, not sliced. That wasn't the right word.
The action was more akin to... To... It, fuck... Her face had the appearance of steak after you force a blunt blade through it; torn, with bits of fat hanging freely, and muscles shredded rather than cleanly cut... crushed bone and blood oozing from what had once been her jaw. The muscles and veins still spasmed and twitched, struggling to continue doing their job.
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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 or 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 Fanchon. What the hell is she supposed to do with 12 soulmates?? At least her odds are better than most...
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Love me through the years by A_Dream_of_Oceans_and_Moons for 1Blue34
Fandoms: Undertale (Video Game)
29 Sep 2025
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And I won't forget you
- Language:
- English
- Words:
- 4,202
- Chapters:
- 1/1
- Hits:
- 6
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You were a normal human. You went to college, you had a life, friends, family, etc. Apparently, the void didn’t care much for happy endings, and you find yourself strapped to a table in an underground lab.
It’s fine, you have plot armor.
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Or, you get sucked into the void and your soul is placed in the body of eight-year-old Sans.
Arc 1: Heritage (1-7)
Arc 2: Hell (8-10)
Arc 3: Home (11-45)
Arc 4: Heart (46-59)
Arc 5: Hostage (60-?)Series
- Part 1 of How To Be A Human Being
- Part 1 of Hounds Of Love
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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
28 Sep 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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The House Next Door by BattleMaiden13
Fandoms: Undertale (Video Game), Underfell - Fandom, Underswap - Fandom, Swapfell - Fandom, Mafiatale - Fandom, Mafiafell - Fandom, Mafiaswap - Fandom
28 Sep 2025
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The first time you met monsters you manage to run into four of them and literally run into one of those four. Now they are apparently moving in next door with their siblings and you can't seem to imagine a life without monsters. On the plus side they tell horrible jokes and have endless amounts of energy. So what could possibly go wrong.
Part 1) Chapters 1-138
Part 2) Chapters 139 - ??? -
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Instead of another skeleton group coming out of the machine, it was you. A teenage girl. Now they have to figure out what went wrong and why this happened. In the meantime, they have their own puzzle and yours to solve in order to adjust to what seems like their new lives.
Or
A random teenage girl came in through the machine and now they have to deal with that and their own issues.
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These are a series of short stories with variants of Sans from different AUs for a potential bigger fanfiction I wanna write in the future.
In these stories, Reader is Gender Neutral and is Referred to as Yin(short for Y/n for convince). I will NEVER describe the Reader or their appearance, there may be times where I have the reader wear clothing and describe it, but it will not be very often so you are free to imagine any outfit in these scenarios that fit with the setting. For certain Sans AUs, I may make you shorter or taller based off my own headcanons for how tall characters are, but that is as far as it will be. For Oneshots with sex or similar stuff, gender neutral terms and compliments will remain as well, but I will write separate sections for those that have either parts.
Terms of endearment will be gender neutral, compliments will not fully describe your appearance, etc. I WANT THESE STORIES TO BE ABLE TO BE ENJOYED BY PEOPLE OF ALL SHAPES, SIZES, ETC. IF YOU FEEL SOMETHING COULD BE BETTER, LET ME KNOW IN COMMENTS HOW YOU FEEL AND FOR CONSTRUCTIVE CRITICISM. THAT IS ALL, THANK YOU FOR READING AHEAD!
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Oh: In which Blueberry learns earlier (through Error, in the Anti-Void) that his genetic material was used to build new beings: Nightmare and Dream.
He's in shock and overthinking until he concludes that, hey, he wants to meet them. He succeeds, not in the conventional way, but he does… Now, we'll accompany Blueberror on his journey out of the Anti-Void, to observe his practically children.
Series
- Part 2 of ❤️🩹💞 Caring for Babybones 💞🥰
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ʙᴇᴄᴀᴜꜱᴇ ᴇᴠᴇɴ ɪꜰ ᴡᴇ ᴀʀᴇ ᴀᴘᴀʀᴛ, ʏᴏᴜ’ʟʟ ꜱᴛɪʟʟ ꜱᴇᴇ ᴛʜᴇ ʀᴇꜰʟᴇᴄᴛɪᴏɴ ᴏꜰ ᴛʜᴇ ᴍᴏᴏɴ ᴏɴ ᴛʜᴇ ᴡᴀᴛᴇʀ ᴀɴᴅ ᴛʜɪɴᴋ ᴏꜰ ᴍᴇ, ᴛʜɪɴᴋ ᴏꜰ ᴜꜱ.
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You’re a scientist! Yes you! And you’re going on a trip through the multiverse! Dw, you did it on purpose