Underswap Stories

984 Stories

I am the classic by KarmaAkabane425
I am the classicby Karma Akabane
Somehow...I've become a sans...and not just any sans.. I'm classic!? What the flip is going on!? Wait why are different sans and papyrus's showing up at my home? I didn'...
Unexpected Helper (Nightberry) by SpiritWolfNura
Unexpected Helper (Nightberry)by Kyran Wolfe
Blue is sick of being treated like a child by his friends and family. He shoves down his negativity in order to stay 'happy' like they want though. Nightmare has had eno...
Can I Stay? (Underswap!Sans × Reader) by Fruityyloopz
Can I Stay? (Underswap!Sans × Read...by Justmonika
[Prolong] My name is (Y/N). I have experienced many resets, so many I have lost count. The only people who remember are Sans, Flowey, and me. The monsters down here are...
About Time by _Irrelevant_Author_
About Timeby A living nightmare
You were always put in second place due to your sister being favored over you. No matter what you did it always seemed that you both were competing against each other. Y...
Yan!Nightmare x Reader (DISCONTINUED) by Silverflame345
Yan!Nightmare x Reader (DISCONTINU...by Moonlake(╯°□°)╯︵ ┻━┻
What will happen when you've grown up with the king of nightmares. Will he let you go, well, we will see The mentioned au's dont belong to me, they belong to their respe...
Becoming Underswap Sans by AmeliaForEli
Becoming Underswap Sansby LazyAmeliaforEli
what if someone in our world becomes US!sans also known as blueberry?
I want to go home.... (Undertale AUs x Reader) by EdgySkeleton98
I want to go home.... (Undertale A...by EdgySkeleton98
You're Frisk's friend, who jumped down the Underground. Not wanting to leave him alone, you jumped after him. After a lot of pacifist routes and resets, you woke up in a...
Me and my brother become sans and papyrus from our own story!? by KarmaAkabane425
Me and my brother become sans and...by Karma Akabane
What if two brothers somehow end up in their own story as the sans and papyrus that they made? They called the story starfell, mostly because everyone in the story is li...
Undertale lemons  by Zen-the-model
Undertale lemons by Zen-the-model
Yep,this is what my life has come to -~- *sigh*
The Last One - Error!Izuku AU by Crosoxon
The Last One - Error!Izuku AUby Crosoxon
"There IS worse fate than death" The cover isn't mine. Just a few warnings: -boyxboy -girlxgirl(maybe?) -blood -su¡cide(kinda) -death
My Love [Yanberry x Reader] by Fandomz_Fanboy
My Love [Yanberry x Reader]by Remus Hisahoshi
You are locked below ground where nobody can find you. Chained to a wooden post in a dark, cold room. You are left with no memory and pain all over. You are left there f...
Keeping You Forever {YandereBlueberry x Reader} by AshiePear
Keeping You Forever {YandereBluebe...by Ash
You fall after being pushed of by the two people you thought that loved you, you thought that you would die. You wanted to die but not like this, ask you hit the floor e...
reincarnated as wyvern (atomictale sans[my au]) by -ILRAHC-
reincarnated as wyvern (atomictale...by Charli Sanders
what if someone from our world died and was reincarnated as atomic!sans/wyvern? please understand that the au of 'atomictale' was made by me and i dont mind if anyone us...
Living with bittys by panpankate
Living with bittysby Panpankate
what would you do if all of a sudden some small skeletons appeared out of nowhere one night and we're so small and helpless you couldn't say no to. So your living with s...
(ՏᗩᑎՏ ᗩᑌ x READER x ᑭᗩᑭYᖇᑌՏ ᗩᑌ)  A Skele-ton Of Harem by YourdailyMOONBERRY
(ՏᗩᑎՏ ᗩᑌ x READER x ᑭᗩᑭYᖇᑌՏ ᗩᑌ) A...by your daily MOON BERRY
You are a introvert who loves undertale and multiverse and loves to play video games and listin to music. What will happen if one day you meet the skele-bros of differ...
Same Person, But So Different (Undertale AU) by TacoGod14
Same Person, But So Different (Und...by Undertale Gaming
What happens when two Multiverses collide? When alternate versions of each other meet in the blank space between Universes? What happens when they try to leave? True neg...
Becoming Error, The Forced God Of Destruction by PinkieKidoCup
Becoming Error, The Forced God Of...by PinkieKido Cup
What if someone is reborn as Error? What if they aren't so bad? What if they're suffering in silence and keeping their job a secret for fear of hate? How will Ink react...
Reborn in an undertale au as a siren by KarmaAkabane425
Reborn in an undertale au as a sir...by Karma Akabane
What if someone died and was reborn in an undertale au as a siren? And not just any kind of siren, but a sans, a skeleton siren. They can change back between full skelet...
A Broken Souled Skele-Wolf (An Undertale Fanfic) Gender Neutral Main Character by FeralMoon0211
A Broken Souled Skele-Wolf (An Und...by FeralMoon0211
Rain is upon first glance is a normal, teenage human. What most people don't realize is that they suffer from extreme depression and is a victim of abuse, all the while...