1 - 20 of 441 Works in Sans/Underfell Sans (Undertale)
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- Part 4 of Sans Aus Things!
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Summary
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.
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- Part 2 of no way off the hamster wheel
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A collection of Undertale UTMV one-shots and small drabbles that I don't want to make entire stories for.
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This takes place in a post Underfell King Papyrus ending.
Struck by under population, King Papyrus makes it law that all monsters left alive by the murderous little human have to procreate. This leaves Fell!Sans and The King himself in a tight spot. There are no female skeletons left in the whole Underground and both skeletons are sure they are the last of their species. Fell!Sans proposes something. With the help of the first Royal Scientist's machine to travel to other universes, he will find mates for breeding purposes.
Tale!Sans is having his first sub heat as a female. This happens when there are only males left and the strongest one undergoes a gender swap. He knows this means Papyrus will have to be his mate.
That won't do. They are brothers, for the Angel's sake! So he does what he does best, HE RUNS.
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( Cover art drawn by Hollowfox on AO3 )
(As of 28/7/25 the first chapter has been rewritten to improve the flow and clarity of the story.)
(I will continue to edit earlier chapters bit by bit. When I'm done, I will announce it in later chapters.)
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Error's done. Fate has been in control of his life for too long. He doesn't want to do this forced job anymore. No more. So he takes a risk.A risk that eventually makes Error terrified of what's to come. More for the ones he calls family than for himself.
Ink realises he's not the only one suffering from fate. He's just as trapped as Error is in this forced job. So Ink does the best thing he could think of. He helps. Well... That leads to more problems for both of them.
Fate will never go easy on them again.
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FGOD Error and Ink are taken by Fate because Error broke the rules, and Ink discovered that Error is experiencing the same struggles as him. The multiverse Sanses must rescue them.
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This series will be split into two parts:
Part 1: Entangled in Ink and Strings 19/?
Part 2: Stitched up at last(FGOD error belongs to harrish6)
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- Part 1 of Free at last
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The village Sans lives in has always felt small, but never smaller than it did now, with Papyrus away. Struggling with his health and his loneliness, Sans leans heavily on his one and only friend- a strange skeleton named Red who lives far out and comes to town once a month.
At the same time, there's strange rumors going around about bloodless corpses and piles of dust being found in the woods...
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Nightmare(s) at the Museum by Cantal3ar
Fandoms: Undertale (Video Game), Night at the Museum (Movies)
05 Nov 2025
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Welcome to the night shift of the Doodle Sphere! Are those statues moving? Nah, it's all in your head, but things don't get started till the Pharaoh's out of his tomb. Except, something's wrong. Dream, are you okay?
Basically, Night at the Museum two in the vast Undertale Multiverses.
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A Well-Respected Man (By The Kinks) by sedimentttttttt
Fandoms: Undertale (Video Game), underfe
09 Oct 2025
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Sans has been mentally unwell for a pretty long time now, so he thought he'd just get used to it. But his NEET ways are catching up to him, so time to get a job! Lucky for him, his boss is ... Sexy?? Whaatt?? Sexy boss??
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Red Bones (Uf!Sans) won a scholarship at the St. Wendell Ebott University, a secluded University in Maine, and goes abroad to study at the Tōkyō Rika Daigaku (Tokyo University of Science) to become a Bachelor of Science. With his late father’s last savings, he flies to Tokyo and takes residence there.
Sans Serif (Ut!Sans) is offered a position as a teacher at the prestigious Tokyo University of Science. Having won a Nobel Prize in Physics 20XX for his findings in quantum physics, studies of multiple alternate universes and The Void. He is ready to impart his wisdom to the masses as a part time professor.
What happens when these two collide?
Drama unfolds!
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Sans makes a joke, but Red doesn't think it's funny. (They still love each other more than anything).
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- Part 2 of Skelz Kustard Week
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The king has fallen.
In the devastation left in the human's wake, a new king is needed. Papyrus steps up to the challenge, assisted by his brother.
Sans is sworn to obey the crown, bound by the Delta Rune. Regardless of who wears it.
But when dark alternates show up and threaten war, Papyrus has to make the hardest decision of his life, and Sans finds out the chains that bind him might not be as secure as he'd like.
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Kustard Week 2025 - a PIE RAT's party-life for me by Anjel_X
Fandoms: Undertale (Video Game)
30 Sep 2025
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Sans and Red are at the yearly all Skeleton Multiversal costume party and as usual, they put as little effort into their costumes as they can.
This is my fic for this year's Kustard Week using all the prompts in one shot.
This fic is set in the same 'world' as the ones i did for Kustard Week 2023, Fontcest May event 2024 and chapter 9 of Skelemonth 2024 and happens in the nebulous future (so there will be references to those fics)
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What Happens in Space Vegas (Never) Stays in Space Vegas by Acoustic_Meatus
Fandoms: Undertale (Video Game)
28 Sep 2025
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Sans and Red's semi-annual weekend bender in Space Vegas takes an unexpected turn.
Or, the boys wake up in the aftermath of a hasty Space Vegas Wedding and consistently fail to make any wise decisions.
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Sans goes to pay his dues at the library but ends up flirting with the librarian instead.
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- Part 1 of Skelz Kustard Week
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Sans was expecting a lot of things when he and his brother faceplanted into a familiar-but-not carpet.
His brother finding his soulmate was not one of them.
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A new series for Kustard week 2025.
Prompt: blue and red makes purple
Ever heard of a yandere bitty? How about two?
Series
- Part 8 of Kustard week
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Childhood friends Sans and Red are thrust back together after years apart, igniting old feelings and buried fears.
A surface AU.
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Maybe one day (NEW VER.) by me_paina for WrittenKinzy18, Clichely
Fandoms: Undertale (Video Game)
18 Sep 2025
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(Note: Reading ClicheAly's Murder to Dust and An Alternate Turn of Events and WrittenKinzy18's Winged AU series will 100% make this fic more enjoyable, but you don't have too. This could be read as a standalone.)
This is only going to get worse before it gets better, and well... Lets pray he won't find a way here because...
No one would survive his massacre.
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ATE Dust accidentally got transported to the winged universe.
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Just a tip to you all, this story will have violence and it may disturb some audiences.If you haven't read ClicheAly's writing, you won't know how gruesome some parts are and you won't know anything about this Dust or his AU, so I highly suggest that you read Murder to Dust and An Alternate Turn of Events before you read mine.
It is also good to know that this is taking place in the Winged Multiverse, so I suggest you read WrittenKinzy18 stories and series.
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4/?(ATE multiverse belongs to ClicheAly)
(Winged multiverse belongs to WrittenKinzy18)
(Drawing by me (Me Paina))
(Undertale by toby fox)Series
- Part 2 of CROSSOVER BETWEEN ATE AND WINGED AU
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Justice is BLIND to evil doing UNSPEAKable acts of kindness by Anjel_X for silverryu25
Fandoms: Undertale (Video Game)
15 Sep 2025
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When a horrible event happens to one unfortunate AU, their saviors end up being the last people one would expect...
Why would the bad guys do such an act of kindness... and is there more to it than that... they'll just have to hope a certain Trio doesn't give them a Bad Time™ in the process...A Kustard fic with an unexpected twist in the form of a Nightmarish poly of miscreants
My Secret Santa Gyftfic for fellow Kustard and pun lover, the SANSational Silverryu!
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He was gone. No warning, no alert, only taken.
Red is scared, Sans feels the darkness closing in.
It's done nothing but rain since he went missing.
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- Part 15 of Typeface: sans-serif