1 - 20 of 2,977 Works in Underswap Sans (Undertale)
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Disclaimers:
Several details in this fic are heavily inspired by 'Blue joins the bad sanses' comic, so go check that out
Canon innacuracies: Passive and Corrupted Nightmare are the same person, Ink is the creator and not the protector, Ink, Error, Nightmare, and Dream, are all gods, Blue, Killer, Horror, and Dust's specific au timelines were all destroyed, and i took liberties with how the void works. Also, no Cross sans will be mentioned, i don't know enough about underverse, and there will be some OC non-sans God/entity/things later on. The fic will be split into parts, each lasting nine chapters.
Schedule: Once a week, on Saturday, Sunday, or Monday, and i will post art or a reference sheet with every chapter. Trigger warnings will be specified in chapter notes. I've never written for undertale before, so please let me know what you guys think :3With that said, the actual plot: After an injured Error crashes into Nightmare and Co's home, a close bond starts to form between the two gods, both forced villains. In light of Ink's attempt to kill Error, Dream finally starts to lose it, and Blue gets dragged along.
Average chapter length is 500-2000
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Slay (SAVE) the Princess by CrossoverAU
Fandoms: Undertale (Video Game), Slay the Princess (Visual Novel)
18 Oct 2025
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You are in a basement in a cabin.
That cabin is in the woods.
In the woods, on his way, is a skeleton
He is coming to kill you.
Will you let him?
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We're back with another year of Inkwhumptobertale!
And this year, we have another twist: another list! That's right: every day, I'll be facing the challenge of eight different unrelated prompts, and I'll have to do my best to cram them all into the story, somehow. Admittedly, there is a low chance of me actually doing that, but I am obligated to use at least three prompts each day, and I'll add more if possible. I'd like to do at least one day fitting all eight prompts into the story at some point in the month, though. So..prepare for chaos!
These characters are not mine!
Series
- Part 4 of Writing Prompts
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The god of death never liked children.
He didnt like people, he didn't like the thing that calls itself his brother even though its just one of many, he doesn't like rules, he doesn't like his king.
But most of all, he never liked children, he hates work. And children are work, that's all they are.
So no, he doesn't feel paternal to the little runt that just happens to look similar to him. Don't ask him again, and also, he will NOT be giving it up. Its his now. Even if he doesn't want it.
- Language:
- English
- Words:
- 878
- Chapters:
- 1/?
- Kudos:
- 1
- Hits:
- 13
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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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Hi- uhm- Story with Blue joins the Bad Guys and FGoD Error In one- Bad Dream, Ink gets a redemption arc.
Das it.
Also, UnderFell, UnderSwap and Undertale Skeleton Brothers are all brothers, so no Red/Classic.
Also, gray Echo Flowers inspo is from the story For The Forgotten Ones. I forgot who wrote it T^T.... But It's a good story, go check them out!
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Undertale Kinktober 2025 hypnosis edition by Chris_ghosty77
Fandoms: Undertale (Video Game)
18 Oct 2025
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New kinktober! One chapter a day for the entire month!!! With a list I made myself, very excited to show everything I've written.
Just like the other ones every chapter contains some form of hypnosis/mind control/brainwashing. I'll do my best to tag but i can't tag absolutely everything so look at the warnings at each chapter or in the table of contents.Series
- Part 14 of Undertail hypnosis series
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The thing about soulmates is, no matter what pries them apart, they always...always find a way back together
Chapters 1-3: Prologue
Chapters 4+: Main Story
*Chapters set to auto release every Saturday!
*This is a rewrite of I Have The Power of Gaster AND Anime On My Side. Same concept, with a bit of a serious feel.*
**Please be aware that this is not like my usual reader-inserts!! This story is in 3rd person pov, very vague description of a female reader. Unnamed (Pet names only). No use of y/n, y/e/c etc.**
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As you walked you failed to hear the screams of terror of a bus going over 100 miles per hour and the sounds of it starting to bust down- it speeds near the sidewalk—the people in it shriek. Their blood curling screams didn’t occur to you, your headphone quality being way too good. Your shoulders relaxed as you stretched your limbs; very much unaware of the danger and pain that would very much make your life way more miserable. You should move out the way. But- likewise, you are unaware. Of death flickering and time excited to cut your strings.
The bus is almost out of energy- and has been stopped.
Or so people thought.
It began to tilt- right where you were very much slowly walking. Andddddddddd—
It didn’t crush you to death.
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Just posted this late despite having this written for a while, but eh
OC-tober Day 7 "Summer Night"
Series
- Part 7 of Birdd's OC-Tober
- Language:
- English
- Words:
- 217
- Chapters:
- 1/1
- Kudos:
- 1
- Hits:
- 19
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You are on death's bed, there is no denying it at this point. Your good friend listened to you rave about an upcoming otome game you have been desperate to play since you've heard of it's creation. Only to sadden when your prognosis would keep you from seeing it in your lifetime. Well this good friend manages to get you a copy. So who would have thought that when you eventually passed on, you'd wake up as a healthy you? With goat ears, nubby horns, and a cute fluffy tail? Also a barrage of skeletons waiting on you hand and foot, calling you their queen... After playing many routes, there is one thing you are sure of... To make sure Black doesn't kill you like he does in the game... yet you don't seem to understand the stark contrast of yourself vs the queen as the skeletons do... and if you aren't careful? Black and the others will fall head over heels for you.
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You are a college student that just want to get yourself together, get a degree and make money enough to live alone in a cozy flat. But what should you do when you struggel with studies and different jobs while sharing a life with skeletons whom seem to don't like you?
Determination won't be enough to keep living in this hell. And a friend of yours make sure you remember that everyday.Now the breaking news:
- I love comments
- No beta reader
- English is not my mother language
- Long time until next update
- I am as bad as Asgore to name and nickname the characters -
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A little bit of one Ink's days, 300 years after Dream was lost.
- Language:
- English
- Words:
- 1,130
- Chapters:
- 1/1
- Kudos:
- 5
- Hits:
- 51
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First attempt at kinktober, featuring my sona Zir!
Very self indulgent.
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You'd never expected to be one of those people who bonded with a random stray, and if you did, you never expected it to turn out like this. The tiny... blob of an animal was cute, affectionate, and melted your heart before you'd even named him. Unfortunately, not everything is as it seems. You've met this lovely creature before, and he definitely remembers you...
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blue is tired of being stuck in the castle. he wants to go home but nightmare doesn't want to fulfill his wishes
Series
- Part 15 of A Berry Kinktober 2025
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when you're blue, i'm red (i wanna kiss your neck and make you purple all over):Asphyxiation by Goatz0805
Fandoms: Undertale (Video Game)
14 Oct 2025
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Lost in the tidal waves of dream, he was shocked when a hand carpet up to his neck. It felt like it was more for support– angling his head so dream could dive his tongue deeper into his mouth. That is until hand squeezed his neck. It didn’t have too much behind it but it was very noticeable to blue.
He gasped like he was out of breath– breaking the kiss effectively as he pushed back. His blue eyes were blown wide in shock. Dream immediately let go, his own yellow eyelights blown wide as if he didn’t realize what he’d done.
Series
- Part 14 of A Berry Kinktober 2025
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It was just supposed to be another in and out. Steal what was worth something and skedaddle. Back to...well, they didn't exactly have a home. Not anymore. Wasn't important.
Back to the issue at hand.
How were they to know who owned the place? What kind of right hand of a powerful mob boss lives in the suburbs? Why does the house look so normal? Why...
And they have a sex dungeon.
Awesome.
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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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Positivity falls and Destruction is left to pick up the ravaged (and melting?) pieces.