1 - 20 of 41,047 Works in Sans (Undertale)
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Summary
The Underswap skeleton brothers are kidnapped by strange sex nagas for explicit reasons.
- Language:
- English
- Words:
- 2,256
- Chapters:
- 1/?
- Hits:
- 0
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Summary
6 weeks after the barrier is broken, Alphys isn't speaking to anyone. Undyne starts to get very worried and tries to figure out how to help her and maybe finally get to kiss?
(True lab trauma)(before the beach scene) (beach scene will come later dw)- Language:
- English
- Words:
- 1,875
- Chapters:
- 1/?
- Hits:
- 0
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Summary
When you were ten years old, your parents sent you to stay with a relative of yours from Ebott. Their villa was situated up on the mountainside, and you loved to explore the forestry. One day the ground gave out and you fell Underground, and faced terrors beyond your imagination. You were missing for weeks.
After you managed to miraculously return to the surface, your parents were relieved - but deeply troubled by your 'delusional ramblings'. They were convinced you were 'crazy', and feared how that would reflect on their reputation. Your doctors advised sending you to an in-patient psychiatric facility, which is where you spent the next few years in intensive therapy and counseling.
15 years later, you're a young adult with a somewhat manageable grip on life. You keep your head down, attend the social events that are expected of you, and try to be as unnoticeable as possible. Your parents arranged a suitor for you, and you're to be wed within the next year.
That is, until, those monsters your parents and doctors tried to convince you weren't real suddenly crawled out from the Underground. And they're a lot different from what you remember.
[[Underfell!verse.]]
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A collection of small moments from a human having a hard time navigating the world. A chance meeting with Papyrus and Sans makes the journey a little easier.
- Language:
- English
- Words:
- 987
- Chapters:
- 1/?
- Hits:
- 0
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OcTEARber 2025, Month challenge. by Lucasisverycool01
Fandoms: Undertale (Video Game), Undertale Multiverse - Fandom
12 Oct 2025
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Summary
This is a month challenge. However, some prompts are missing. I have combined it with another challenge I’m doing. I’m doing both a writing AND drawing one. I’m doing this over on Tumblr, my tag is the same as on here.
- Language:
- English
- Words:
- 7,401
- Chapters:
- 8/8
- Hits:
- 5
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The Doctor's Descent by Feanyx1
Fandoms: Undertale (Video Game), Doctor Who (2005), Deltarune (Video Game), Doctor Who
13 Oct 2025
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Summary
He thought that the radiation would kill him. He thought that his time as the Doctor would come to a sad and brutal end. He was wrong. And that was so much worse.
In his efforts to find himself, and without his companions, he accidentally stumbles onto a monstrous civilization miles below the Earth. With his newfound DETERMINATION and some new allies, he'll come to realize what it truly means to be a friend, and learn how to live his last lives with his head held high.
And make sure that, just this once, everybody lives.
OR
Undertale but the Tenth Doctor replaces Frisk. Fluff, angst, AUs, and timeline shenanigans ensue.
*No knowledge of Undertale or Doctor Who is required, though it is helpful if you've experienced at least one of them.
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The Need to Persevere and The Need to SAVE by DuckyDuckyQuackQuack
Fandoms: Undertale (Video Game), Horrortale (undertale au)
13 Oct 2025
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Summary
Sans has a mission, and Aliza is a part of it.
She will persevere through anything he puts her through.
She has to get out of this hell hole. She has to help Sans with his mission. It's a good thing these things align, but it sucks that they align in such a way-- Aliza doesn't want to hurt anybody.My work for AI-Less Whumptober! It's all one continuous storyline, this is NOT a one shot book (I'm bad at those lol)
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That hall, bathed in rays of gold. The comedian manages to convince the fallen to RESET. Not that they were opposed to it in the first place. They do it right, this time, and their life on the surface begins. Perhaps, for once, they gain love, instead of LOVE?
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Please note: English is not my first language. Thanks for understanding.
In a multiverse built on creation and destruction, timelines flow according to unchangeable laws. As resets repeat, 'anomalies' begin to appear, threatening the very existence of AUs. Ink, the AU guardian, struggles to maintain order while navigating conflicts with troubles and protecting his friends. Amidst uncertainty, trust and reliance between him and Dream deepen, revealing hidden vulnerabilities and the weight of past failures.
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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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The Last Amalgamate (The Peacock AU edition) by WingsOfShen
Fandoms: Undertale (Video Game), Undertale Yellow (Video Game), Kung Fu Panda (Movies)
12 Oct 2025
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Summary
After millennia, the barrier keeping the monsters Underground has finally broken. The entirety of the Underground does not remember what happened. All that is known is that a living human child was involved.
Before starting a new life on the surface, Frisk joins Alphys in sending the final amalgamate back home to her family, making new friends along the way and giving them their much-needed happy ending.
(Based off "The Last Amalgamate" by VyletBunni and the DeltaTraveler team. Credit goes to them for the animation series.)
Series
- Part 4 of The Peacock AU
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Summary
The year of 194-.
The 1940s were not a great time for many people, and those people also include a certain family; Klaudia and her family were immigrating, in the hopes of not being caught and put into the worst fate imaginable, only that, with curiousity, Klaudia found herself slipping and falling inside a wretched hole in the mountains of which her and her family had set up a hiding, never to be seen again.. by humans, that is.
The underground was in a crisis, its weather and resources were in a dangerous stage, and the monsters had become desperate. And desperation leads to rage, and rage to violence, and they knew they needed one more soul, a single other soul to finally escape their confinement underground. But they were also smart, theyd play their cards right and try to fool the poor girl to falling into the beartrap, earning her trust, however.. she was, too, as smart as they.
- Language:
- English
- Words:
- 531
- Chapters:
- 1/1
- Hits:
- 3
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A world where your impact was heard elsewhere by dream_sky
Fandoms: Undertale (Video Game), Undertale Yellow (Master Sword)
12 Oct 2025
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Summary
"A long, long time ago, another human fell down here."
"Injured by their fall, they cried out for help."
"...But nobody came."
Or
Chara didn't wait as long for help, and by the time Asriel works up the courage to investigate the cry, they're already gone. The butterfly effect (and the addition of a bunch of my headcanons and ideas) does the rest.
(currently in hiatus purgatory)
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Kinktober 2025 by littlexsiren
Fandoms: Undertale (Video Game), Mass Effect Trilogy, The Avengers (Marvel Movies), Star Wars - All Media Types, InuYasha - A Feudal Fairy Tale, Five Nights at Freddy's, Naruto (Anime & Manga), Call of Duty (Video Games)
12 Oct 2025
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Summary
Tis the season!
Welcome to my first ever Kinktober Collection! I figured this would be a good challenge to get me back into the swing of things so I can finally update my other fics. This one shot collection will contain my favorite fandoms and mostly be reader-insert and Original Female Characters (a mix of 2nd and 3rd person POV). I make no promises that I'll have 31 one-shots for y'all to read, but damn I'll do my best to give ya somethin'.
Remember, this is an ARCHIVE that gives you the option to filter out tags you DO NOT like to read. If you don't like it, don't read it.
1. König/Original Female Character
2. Stretch (Underswap Papyrus)/Reader
3. Sans/Reader/Red (Underfell Sans)
4. Black (FellSwap Purple Sans)/Reader
5. Rock Lee/Original Female Character
6. Original Male Turian Character/Reader
7. TBD**I'll be updating relationship tags as I upload chapters & tags are subject to change**
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IT'S THAT TIME OF THE YEAR!
Kinktober time~!So yeh this is basically short drabbles of smut. Some will be longer, some will be shorter but I'm gonna try my best to make them juicy~
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the big kinktober 2025 special by ohitsthatguy for YeeSans
Fandoms: Undertale (Video Game)
12 Oct 2025
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so uh
i am writing and dedicating all these works to a very very special friend of mine, pookie when you read this, hi ily <3be aware i have no shame so a few of the chapters are on the really weird side of things, so please read over individual tags and warnings provided
happy gooning and spooky month for you all <3
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SOUL's Divine Fire by Virtual_Faye27
Fandoms: Percy Jackson and the Olympians & Related Fandoms - All Media Types, Undertale (Video Game)
12 Oct 2025
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Summary
Bridget Hartkroft would like to state, for the record, that when she left Camp she didn't expect to run into an entirely NEW Pantheon! That seemed like something a Big Three child or one of The Seven would deal with. Not a crippled daughter of Hephaestus that wanted to get away from her traumas and stop weapon making.
But here she was; Nowhere near her fellow Greeks, the Egyptians, Norse OR the Romans and she HAPPENS to be nearby when Magic-born Monsters finally escape their magically sealed prison and now she encounters a lot of Skeleton Avatars of Gods and their Mortal followers! At least with the creepy ones they kill the things after her and can be banished if she throws sharp pointy things at them when normal offerings don't work. The 'good' ones make her wish she could jump into fire like her half-brother could just so they would Leave Her Alone.
For the Undertale Multiverse when a new AU is born with almost as much divine energy coming from it as Reapertale they just HAVE to investigate! And that one weird SOUL-ed kid threw food and weapons at them they just HAD to stick around! But why was she so sad and angry all the time?
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Skeletwins Sans' diary.
(Note: I HIGHLY recommend reading the main Skeletwins story before reading this fic. Spoilers for Snowdin Adventures with the Skeletwins ahead.)
Series
- Part 14 of Skeletwins Side Stories
- Language:
- English
- Words:
- 748
- Chapters:
- 3/?
- Hits:
- 10
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For a while now, Mettaton has admired Papyrus from afar.
On the cameras in the lab, he saw his face on the screen.
Everything he did, everything he said... All of it was enough to make a robot such as himself flustered.Eventually, he asks his friends, Undyne and Alphys, for advice on how to navigate these new, exciting feelings
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Once monsters had been released from the underground, the stage was set for a new revelation in the world of science. many people saw against integrating monsters into human society, but you encouraged it. with the discovery of magic and how it can interact with modern science. Now with the new applicants, your discovery will only increase and maybe your relationships with monsters, too. stay tuned for new journeys with your monster friends and learning things that have...multiverse impacts.