1 - 20 of 41,242 Works in Sans (Undertale)
Navigation
Listing Works
-
Tags
Summary
After Basil’s death, Sunny runs towards his home in an attempt to end it all, but Aubrey follows him and she prevents him from dying. Sunny tells her the truth and now they have to face it together.
After moving, they find themselves camping until something happens and now the two will travel together in order to escape the Underground filled with creatures that were only believable to see in fantasy books.Notes:
the Undertale tags are there because I want to make an Omori x Undertale fanfic, but there won't be anything related to Undertale during the first two chapters except for some references to Mt. Ebott and its legend, but around Chapter 3 or 4 onward, the Journey through the underground will begin!
So stay PATIENT!Series
- Part 1 of OMORITALE: Fallen Down (Fan-Series)
-
Tags
Summary
The RESET button is pressed. No surprise. Another wound inside Sans tells him this wheel will never let go. The world around him melts, everyone forgets themselves, forgets what happened between them. The ketchup flies back into the fridge and dissolves with it into nothingness.
He accepts this with restraint, ready to face the void, to be a toy in someone else's hands.
But then he is torn from the shroud of nothingness, a golden light penetrates Sans, and he opens his eyes in a different... place.- Language:
- English
- Words:
- 6,157
- Chapters:
- 2/?
- Hits:
- 11
-
Tags
Summary
It's been six months since monsters left Mt. Ebott. In that short amount of time they'd manage to blend into society as best they could, save for the heart of the city. Anti Monster gangs run those streets, scaring many of monsters away. These gangs forced monsters to stay on the outskirts of the city, close to the mountain. Then one day, the university that you work at dared to break social norms and hire a couple of monsters. Nothing could prepare you for what would happen next.
-
The Chemistry of Love - Remastered! by MischievousManiac
Fandoms: Undertale (Video Game)
29 Oct 2025
Tags
Summary
It’s been nearly six months since monsters broke the barrier and moved out from under the mountain and alongside humans. There was a lot of panic when they first surfaced. Suddenly, these beings of myth were no longer just myth: they were living, sentient beings that want to be given a chance to live and grow just like everyone else.
Maybe it was their calm demeanor that kept most humans from lashing out violently at them. Or maybe it was because they surfaced with a human child that wasn’t afraid of them. Either way, monsters slowly started working their way into the city. The neighborhoods and shops near Mt. Ebott were the first to accept monsters rather than turn them away.
Since you lived a little closer to the heart of the city, your life wasn’t altered all that much by their appearance. Every so often you would hear hushed whispers that some monsters tried coming further in only to be driven back by the Anti Monster gangs that started to plague the city, but you had never seen one. Certainly, never dreamed of working alongside one, only to fall in love with him, either. But fate is a mysterious thing.
- Language:
- English
- Words:
- 2,790
- Chapters:
- 1/10
- Kudos:
- 1
- Hits:
- 14
-
Tags
Summary
when you've lived your whole life in the dark, how are you supposed to know to look for the light?
-
october 29 : guilt
Series
- Part 6 of whumptober 2025
- Part 1 of UNDERRAVEL
- Language:
- English
- Words:
- 1,100
- Chapters:
- 1/1
- Collections:
- 1
- Hits:
- 10
-
Tags
Summary
So, I heard you like skeletons...
Reader insert prompt fills for @skeletonh0e's sans-centric Kinktober challenge on tumblr
-
Tags
Summary
You save a skeleton monster from dusting in an alleyway, good for you. Unfortunately tho, he might be a tiny bit smitten and a real pain in the ass
-
Tags
Summary
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~
--------------------------------------------------------------------------------
-
Etiquette of Possession by Pipsqueak (Skyhon)
Fandoms: Undertale (Video Game), Deltarune (Video Game)
29 Oct 2025
Tags
Summary
You raise your eyebrows and gesture towards the back. “By all means. You’ve not introduced yourself to the others here… although I suppose that makes sense, given your mission.”
“i think that mission is a lost cause, to be honest. kris is sorta impossible to find a match for.”
“Well,” you say, “at least there’s wine, then.”
“exactly.”
There’s a pause in which you both lock eyes and blatantly stare at each other, but this time there is not a hint of hostility. It must last nearly a full minute. Somehow, this experience is not at all uncomfortable or weird. Paradoxically, the fact that it isn’t weird makes it weird.
“care to join me?” he finally asks.
And who are you to say no?
—
Or: Sans is the Judge, and you... you are something else. Something that's been sleeping for hundreds of years, under the Deltarune Palace. Something he’s needed, and finally has.
Unfortunately, being possessed by a spirit of violent judgement kinda has its own quirks, and Sans is really fucking stubborn.
Fortunately, so are you.
- Language:
- English
- Words:
- 6,731
- Chapters:
- 1/?
- Kudos:
- 5
- Hits:
- 37
-
When life gives you a gun, you're gonna shoot. by Quinme
Fandoms: Undertale (Video Game)
29 Oct 2025
Tags
Summary
One moment you were on the call with your friend, the next you are in a shady dark alley, pressed by... a crocodile with fedora?
Life is confusing, and you have no damn idea where you even are and what will come next.
-
Spending Spring Break Underground by 4Trixs_Animations3
Fandoms: Undertale (Video Game), 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia (Anime & Manga)
29 Oct 2025
Tags
Summary
Once upon a time many centuries ago, the world was ruled by two species: Humans and Monsters. Both of these creatures thrived together using their special talents to help one another. That was until the humans declared war on the monsters out of the blue. This led to the monsters to be banished beneath a mountain.
But rest well when I say the humans suffered their karma. Without monsters they soon lost their magic, along with their way of life. They developed their own powers called quirks, with this power came the raise of heroes and villains. Quirks were quick to spread until only 20% lacked them.
It wasn’t long before magic and monsters were reduced to legend. This led many to climb the mountain to see if the legends were true, only to never return. This was because of the heartbroken monster king who put a bounty on every human who fell.
When the last human fell, the monsters were ecstatic. Finally they’ll be free to wander the surface and feel the sun and the rain again! But unbeknownst to them, they have become even more trapped than they had before. With each reset the monsters were forced to live the same day over and over without anyone knowing ... .Well, almost everyone.
-
Tags
Summary
Spanning over ten years, this huge fic will be split into ten parts for each year.
This fic is Alphynecentric, with Alphys at the helm. This is a fic that came outta nowhere (as they all do) and hasn't quit since I started. I have no idea where this will go. All I know is that it is very emotional, romantic, and rather silly.
Just enjoy. This may be my last fic for this fandom.
Series
- Part 1 of Ten Years
-
Tags
Summary
What if we got to see a more in-depth interpretation of monsters returning to the Surface? Here's my interpretation of it - through the POV of Mettaton.
- Language:
- English
- Words:
- 895
- Chapters:
- 1/?
- Hits:
- 16
-
Tags
Summary
The Multiverse was frozen.
Deep, black ink dripped from the code of AUs.
Nothing new was being created, and nothing could be destroyed. Everything felt definitively fuzzier at the edges as the balance of energies refused to tip for anything...The entirety of the Multiverse was decaying, slowly but surely, and it was all because a certain Creator has gone missing...
-
Tags
Summary
The Barrier is down, monsters are walking the streets, and reality just got a lot stranger.
Rhea is human, unprepared, and stuck in a house full of wildly different, unpredictable skeletons. Some are warm, some dangerous, all impossible to ignore. Pulled through by a mysterious machine, she’s trapped under their watchful eyes while the multiverse starts leaking into her life.
Rhea navigates the household of chaotic, flirtatious, and often deadly skeletons, while trying to come to terms with her new fantastical, but very real reality.
Darkly funny, magically strange, and dangerously charming. An urban fantasy reverse-harem story about survival, trust, and learning to live among the bones. -
Timeless Justice by TheDoctorWD
Fandoms: Undertale (Video Game), Undertale Yellow (Master Sword Video Game)
29 Oct 2025
Tags
Summary
After countless resets and endless repetition.. something has changed. The timeline has began shifting, changing its path for the first time in a long time. A new path Flowey hasn't seen before.
Well, it might take Clover longer to reach Asgore but Flowey has all the time in the world after all. And seeing something new finally happen has piqued his curiosity. Drawn in by the unfamiliar, Flowey watches with morbid fascination as Clover is not able to give up his soul this time. Encounters shift, monsters react differently, and the world itself begins to remember things it was never meant to.
Events shuffle. Characters act out of turn. Rooms appear where there were none. And for the first time in countless resets, Flowey doesn't know what comes next. Clover's fate is uncertain. Though Flowey knows he will get those human souls, no matter what.
Series
- Part 1 of Fractureverse - UT/UTY/DR
-
Tags
Summary
Years after monster and human society merge, a young monster returns to the Underground with the intention of finding a story to tell. She finds that story in a stack of well loved letters between one Cathode and Mailman.
NOTICE: The final arc of this story contains implied suicidal ideation and serious self-destructive behaviors. If you are not in a position to read this sort of thing, you can stop reading after Chapter 22 and skip from there straight to the epilogue!
Series
- Part 1 of Dear Mailman: Yours, Cathode
-
Tags
Summary
Fell is alone at home because his Bros got Gaurd stuff to do and his lovely datemate and boyfriend is training at nightmares castle.
His mind starts to wander and he ends up a little less high and DRY then he expected to end up today.
- Language:
- English
- Words:
- 1,790
- Chapters:
- 1/1
- Kudos:
- 1
- Hits:
- 33
-
Tags
Summary
Undyne thought it would be fun to summon a demon, others didn't believe it would happen but agreed, and they end up summoning you
-
Tags
Summary
Sirens don't really NEED to eat humans but they're pretty delicious so you are out to hunt one, but things change when it's a monster you lure into the sea instead