Undertale AU x Crossovers
199 stories
The Generous Designer (Au sans x Male Reader) by Cordelia5883
Cordelia5883
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Okay so I did wheel decider to help me with y/n love Interest for this book. So I did One Love Interest, Two Love Interest, or All Au sans. And the wheel has chosen All Au sans as Y/n Love Interest. This is an au I made called Harmonytale. No war happened and to maintain balance between humans and Monsters, the mages and monsters made six crystals (Base on the Element of Harmony). Also this will be similar to Overtale and Undertale (with y/n and his family being the human version of Gaster, Sans, and Papyrus) I'll explain more in the bio. My Little Pony: Friendship is Magic belongs to: Hasbro Studios & Lauren Faust (The Creator) Undertale belongs to: Toby Fox Undertale Aus belongs to: Their rightful Owners Glitchtale belongs to: It's rightful Owner. Oc belongs to: Me Harmonytale belongs to: Me Picture: Belongs to there right owners, Some are mine. I'll let you know which one is mine.
𝚎𝚊t. (horrortale sans x reader) by HeyitsSmile
HeyitsSmile
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(Y/N) has always had a problem with sleepwalking and night terrors, ever since age 10. As she grew, her night terrors became less frequent - but her sleepwalking became more dangerous. She would wake up several blocks from her house, or sitting in her parent's car, and all efforts to stop the dangerous habit were pointless - she could undo locks, move seamlessly through her home and even hold simple conversations as if she were awake. It was almost as if something was drawing her away from home. One mid-winter morning, a blizzard kicked in, and (Y/N)'s boss insisted that she stay home. She took this as an opportunity to get a short nap in, only to wake up in the deep, snowy forest of Mt.Ebbot, miles from home. With the world spinning around her, she makes her way into a cave to get shelter from the storm, unknowingly bringing herself to the mouth of the Underground. Inspired by the lovely CrusnikRoxas's story, 'Cadaverous', and music by Jack Conte, particularly 'Eat'. Content warning for explicit gore, (self) cannibalism, self harm and sexual content. Cover is temporary. Reader is not Frisk, Chara or Aliza. Can also be found on my AO3, HeyitsSmile.
Reborn as sans (Underdark) by HunterWildYT
HunterWildYT
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A 15 year old girl named Sara was walking back home from her high school lost in thought when she suddenly felt a huge amount of pain. Her head hit the ground and she blacked out.
Yandere Sanses X Reader (Not A Story! Just Headcanons!) by Glitched_Dreams
Glitched_Dreams
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Basically how I imagine Au Sanses are as yanderes.
An Error's Doll by EroseWisp
EroseWisp
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You didn't have a bucket list or anything, but you wished you could've at least read a few more fanfics or done literally anything fun before dying. Oh well, at least you didn't have to socialize- Wait. Since when did dying mean becoming a doll in an Undertale multiverse? How did this happen?? This was inspired by a ton of reborn and reincarnated as Undertale characters fanfics and some other awesome stories! The main inspiration was 'Little Dream Doll' by KassyxTheDumbFox, and they got the idea from Firehedgehog's 'Idea Factory'. Beware, this story is fan fiction and is not canon, will include ooc characters, and I don't own Undertale or any of the characters, if you don't like that please read something else. This is my first story so there's no guarantee I will update regularly if at all, this is mostly self-indulgent. Btw, the cover's mine, please don't use it.
Tiny dancer Dancetale Sans x reader (COMPLETED) by Kath1908
Kath1908
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4 years after monsters came about Ebbot (Y/N) was friends with the Dreemurr children. Being the master dancer that she is can gather her magic to do amazing things. Having been through a lot in the short 19 years of life. She finally meets a handsome monster who knows her big brother and who understands what she goes through. What will happen between these two?
Z-Tale ~*~ Undertale x MHA Crossover Fan Fic by IrainandthunderI
IrainandthunderI
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Izuku tried to take Katsuki's advice and kill himself, but to find him on the couch in Sans and Papyrus's home in the underground with no memories of his previous life!! Izuku realized that his trip here made him a monster with a partially human soul with low HP. How will Izuku adapt to his new life? --------------------------------------------------------------- Katsuki has entered UA a while ago. His childhood friend, Izuku Midoriya has been missing for about 1 and a half years now. But when a Villian attack happens, he finds himself, and some of his classmates in a strange place, and greeted by.......... A talking goat? Started: October 8th, 2020 Ended: ???
Your Fault ~ Underfell Fanfiction by DragonzRawesomE
DragonzRawesomE
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{COMPLETED} Sans' life isn't easy, and living in an Underground society filled with torture, rape, and murder doesn't make it any better. Every single day is a struggle, and Sans tries so hard to fit in with other monsters and live up to his brother's standards, but sometimes it's just too much. Will Sans be able to pull through, or will the darkening thoughts that are engulfing his mind and Soul take control, and swallow him up into a void too deep and dark to ever imagine? DISCLAIMER: UNDERTALE is owned by Toby Fox. UNDERFELL belongs to the AU Community. COVER IMAGE edited by me. I do not own the original image. PLOT/STORYLINE belongs to me. The events in this story are not canon and are simply for the entertainment of myself and my readers. Any OCs mentioned in this story also belong to me. MATURE CONTENT WARNING: The events in this story contain mature content that some readers may find triggering and/or disturbing. Read at your own discretion. Thanks!!
Reincarnated as Dream with Differences by Xalatea_Zennia
Xalatea_Zennia
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(Discontinued) A random teenager dies, and no they don't get hit by the Isekai truck unfortunately. The 'driver' couldn't make it on time. This teenager wasn't really random, they were kept in a lot of people's hearts but unfortunately, all good people come to an early demise. Problems arise, something is clearly off with everything. Was this all planned all along? What would the gods think about this newly reincarnated soul in the body of a powerful being? What would YOU do? Hey what about that purple thing- ⚠️Warning⚠️: In this book there is certainly angst in it so I'm adding this warning. This book contains multiple examples of (but not limited to): • Mentions of Torture • SA • Gore • Violence • Suicidal Thoughts • Attempted Suicide But not to worry readers, there are also good things such as Fluff relationship. After all, every book contains some bad scenes and because Dream and Night has bad backstories. Feel free to ask any questions and I will answer it.
The Girl who speaks in Hands  Star Sanses x Reader x Bad Sanses by Multiverselover
Multiverselover
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You were born different from any human, you could only speak in wingding language. Everyone treated you different instead of your parents who understand the language. One day your life changed when she fell through a portal leading to a different world. During that time you met three skeletons who were called the Star Sanses and were kidnapped by the Bad Sanses as a hostage to lure in the Stars.