Undyne Stories

Corporal Adrian Shephard, a US Marine Corps soldier assigned to the HECU division, was sent off to Black Mesa for 'cleanup duty'. Despite the hell he went through, the marine somehow manages to escape the dangerous, alien-ridden facility against all odds and, after being 'detained' by the ever elusive G-Man, is then assigned a new mission many years later... to the UNDERGROUND! Accompanied by Chara Dreemurr, the first fallen human turned apparition, the two journey through the unprecedentedly large Underground for one, very specific goal... but what exactly was it? And is that all there is to it? In... time, all will be revealed.

If given the chance, would you start over? After falling into a timeline where nobody was murdered, his mother never died, and his father was never erased, Sans should be ecstatic that he has a second chance with his loved ones. But there is no denying the trauma he'd been through, either. Everyone is supposed to be dead, after all. What if Frisk comes back to take it all away again?

What if there was an anomaly in the Underground? No, not Frisk. Not Chara either. Someone else entirely. How could a few measly children stand to this supposedly immortal foe and save the Underground from destruction? Is it even possible to do so? Only one way to tell... ~o0o~ Disclaimers before you start! •There is NO fanon ships. That means no Soriel, Papyton, etc. The only ships are Torgore (in the past) and Alphyne. •This is NOT an x reader. I dislike those types of stories. The reader will have no part in this, and they will not be shipped with anyone. •This exists outside of canon to an extreme. For example, Frisk is the second human and not the eighth. •There will be OCs, but only for a few humans and they still technically exist in normal Undertale. •There is a sequel. I'm planning on rewriting it after this one, as it is much more random and definitely needs it. Clanky, plot holes/retconning, etc. It's more of an OC thing, to explore them and their issues, than an Undertale thing, but it has its similarities. •There will be some explicitives. It won't be unnecessary or excessive, only when it fits the situation and character. I will not be using any slurs, as that's just plain disrespectful, even if some of them apply to me. Credits: Undertale, obviously, created by Toby Fox and Temmie Chang. "The Time Before" by ANinnyMouse42 is the backstory for Sans in this AU with some adjustments (mainly since that was very close to my original idea before I read it and I don't want people to think I copied their masterpiece or smth, if you haven't read it please do so, it's really good). Some things will be in reference to the other books in the trilogy or "From War to Science" by Emotistic-optimistic. If you haven't, read that too. It's really good (along with its sequel). The cover was made by me! Have a good day! (Also, the title is a placeholder, if anyone has any ideas that make more sense, please let me know.)

It's a fall into darkness... a world of starving monsters. All that would do anything to survive. And that includes catching a human like you.

Neutral. His life could be much worse. It could be better. At least the kid aborted the genocide run this time. But when are they done playing? He wasn't the only one getting tired of it. Not anymore more... He waits for them to reset but it doesn't seem to be happening anytime soon. Bad things happen, and Neutral is starting to doubt if even their remaining queen could make it alive. "Don't do this to me. Please."

All the monsters have left the underground and Sans is dealing with more than he had bargained Cover art does not belong to me

Entirely new reimagined of Glitchtale where there would be many changes that are not seen in the show. Some of them may be controversial, but some I think should've been since the beginning I suck at writing still so I'm trying my best Credit to Toby Fox for making Undertale in the first place since it's a wonderful game I love it story Glitchtale however, is a different story. It's creator is very controversial so I would try my best to stay away from keeping a lot of the things from the show. I know it's an AU but I consider it as a show some of the changes I can say right now is that Chara will now be a female look at a bit controversial, but it would make sense because frisk is a male and Chara should be the female that's the change I would do, but I'll get to all the changes soon enough since the first chapter of release is all the changes though stay tuned Also, I'm 17 while I'm doing this

CONTAINS SPOILERS FROM BOTH PACIFIST AND GENOCIDE RUNS After a horrible situation, I (Y/N) scaped from home to avenge my (sibling). In a failed attempt, I got lost and fell through a hole, in there I found another world... "the underground". I meet many friendly monsters, one, specifically, changed my whole life. Both of us will try to give the monsters the liberty they deserve. And this is how all happened... (Cover made by me :3)

On a dark, windy and rainy night in a bad part of Chicago, a skeleton named G, walked home from work. He doesn't normally walk home, preferring his motercycle, or even his teleportation powers. But something made him walk this night. Fate. G finds himself saving a young girl from a horrific death, and then taking her home to keep her alive. What he didn't expect, was for the girl, much older than first appeared, to flip his whole world upside down. A curse, layed on his SOUL many years ago, may have the second chance of being broken, but DEATH has other plans. To make matters worse, the girl has a deadly disease, with little hope of survival. Can G save the girl who he has sworn to protect and take care of? And in turn, can the girl break his curse, and let him finally live the life he was ment to? 《GasterSansXOC》 (Frequent updates, and this promises to be a very long book)

A bunch of Undertale short stories! ... Which, despite the cover, are not only about Frisk, Flowey, Alphys, and Sans. There are other characters in there too. Aww, who'm I kidding? Probably 90% of this is skelefam fluff 'n' feels.

[3rd book] So it's yandere Undertale One shots because I can. Also because some characters just kinda need to be more recognize. Slow updates? Or it will just Update at random. Also there might be some errors so sorry about that. Started - 4/9/23 Ended - 5/31/24 I don't own Undertale or the Characters! Not the Cover I just edited it!

Kyra falls into the underground, while there she finds that her connection to the monster realm goes deeper then she thought. Cover by @rykosen Undertale belongs to Toby Fox

Your mother is an alcoholic who abuses you terribly both mentally and physically. You father left you when you were little which made your heart hollow. You've been trapped inside your cramped house for as long as you can remember. You've never been loved. You've never loved. Most chances is that you never will. Until you meet a lazy, pun-loving skeleton...

Was this truly the last RESET? Sans wondered. But he knew only Frisk would tell, only this young girl would decide his future. He hated the thought of it at first, but hatred began to grow numb after he figured out he had no say in his own future. He had to admit though, Frisk was pretty reasonable, it was Chara who was the maniac. But she was gone now, so what was the anticipating, eerie, feeling that he had in his bones? The feeling that something wasn't right, of course, this timeline was already incredibly strange. The feeling sat in his in the pit of his stomach, tying itself into knots, until that fateful rainy day when all of his questions would be answered. So basically, this is a fanfiction of a fancomic of the game Undertale. Look, I'm gonna admit, I'm little stuck in the Undertale fandom, so this is my of slowly crawling out of it. Anywho, I strongly suggest you read the fancomic which this fanfiction is based off of, DeeperDown, before reading my story. Here, I'll give you a link. http://gettingdeeperdownwithundertale.blogspot.com/ Anyway, enjoy the story, it took me about 11 months to write, so please consider enjoying it, seriously. - Ya Boi, Fox

Spoilers for after Undertale and after Gravity Falls! The twins are coming back to Gravity Falls for their winter break. However. The mountain just by Gravity Falls had a strange event a few weeks after the twins left. Monsters from the fabled "Underground" started coming out of Mt Ebott. With their savior, Frisk. Now Frisk and their monster family live peacefully in the nearby town of Gravity Falls. What shenanigans will the twins get up to this time? What will they discover? *This takes place after Gravity Falls' Finale and Undertale's True Pacifist ending!* The original Gravitytale idea as well as the intro music used was made by the amazing Jeffrey Watkins. Check them out on Youtube and their story on AO3! I thank them for inspiring me to make my own fanfiction. This is my first story and first time writing a story, it might not be any good, but do enjoy!

After escaping the Underground and getting clipped by a truck, an amnesiac Sans ends up in the home of a vet, a doctor, and their daughter. He's certainly nothing they've ever seen before, but they can't just let him suffer either, so he becomes the unlikely son. So when Frisk falls into the Underground, Sans must return home to the place he was born and raised. Can he and Frisk free monsterkind from the mountain, or will they make a home Underground with the family Sans lost long ago?

Tiếp tục bên nick @nhi26122004 nhé <3

Your name is y/n, you are an angel that lives with your abusive father. One day, monsters are released from MT. Ebbot and are welcomed into society. Unfortunately for you, the beatings just got worse. Then high school started, even though you got bullied a lot, you met some monsters that might make things become better. And one of them wants to be more than friends....

A young teen girl named Sonja who fell down to the Underground which she has the ability to transform into a Mermaid when touching water. Sonja also has powers which she has heating and freezing powers which it'll help her out in her journey at the Underground.

Sans the skeleton is a resident of Snowdin in the Underground, and life as he knows is mostly alright. He had his optimistic, egotistical brother, Papyrus, his mysterious friend in the RUINs, Grillby, the bartender at his favorite place to stay, and many other buddies and acquaintances he'd made over time. But one day, when the friend from the RUINs makes a strange request of Sans, he couldn't help but give her his word and make a promise. However... When he sees the subject of his promise exit the RUINs- A strange, wayward, dust-covered human- Sans questioned whether he'd be able to stay true to his word. (Feel free to leave suggestions for other stories you'd like me to write in the comments! None of the art featured here is mine.) UPDATE: Uh, so, my headcanons have changed quite a bit from when I wrote this, including Sans' attitude at some points, the Mettaton NEO situation, the Alphys evacuation, and other things. Well, enjoy an inaccurate, probably cringy story! I hope you like it anyhow.