What if Frisk from Undertale went to the world of One Piece? See what happens as Frisk goes on a new adventure!

Stories speak of a mountain where children have gone and never returned, unknown of the mystery which lies within it. Now history repeats itself as a child falls but with a twist as another joins...and to think a mild stroll got him into something thought of as fairy tales.

La vie de Léa change du tout au tout quand des monstres surgissent de nulle part pour l'attaquer et qu'elle se retrouve contrainte de vivre dans une académie loin des humains.

For ages, the Void godness has to sit and see how her multiverse was fill and filled by AUs of her Universe, Undertale, she hated them at first, but now all her hate fall in their creator, Fate's spawn, Ink. Meanwhile, in another Multiverse, other Void God makes a deal with the ruler of Hallownest.

Those who would tamper with fate will meet one beyond their hopes and despair. Those who would seek to make a better world will always have the misfortune of never living within it. Some might not have a choice, however. A choice to live a happy life. A choice to tamper with fate. Or a choice to destroy the world. Not all are fortunate enough to choose their fates.

During the absolute genocide run, Sans killed the human. Instead of letting their soul shatters, he took the shards and absorbed it. After absorbing the soul, he turned into a human and absorbed the other 7 to break the barrier. He then found himself in an anime-ish world. Now, he must fight against a darkness that lingers in this world. Finally, the art is not mine.

Fredbear had been through a lot in the underground, and now Springbonnie is no longer the person he once knew... but Fredbear learns there's a monster that can help.

"This was never meant to happen, you should have just brought them back." Player said as he went to delete her , but then something caught his eye. The Monika lover smiled as he looked at the Heart. "Maybe you can still learn." He moved her file over to UNDERTALE and opened it's files. He was finding a spot to put her, hovering over Frisk's. Then the lightning struck them..

in this tale madoka falls down into the underground and has the power to save and reset and each time she does someone else is with her and monsters do not want to fight her ( M for future chapters )

When a hiking accident sends Frisk to the depths of Mount Ebott, he's forced to adapt to his new surroundings. Meanwhile a restless prince seeks for adventure...and a new visitor just might provide the means to fulfill his cravings.

Naofumi ends up in the Underground with no idea how he got there or what he was trying to do before that. What will he do in a world where the monsters are trapped and the key to their freedom is taking his soul?

A Nation, left with it's King dead. A Village, with a pariah about to be tried. A Child, desperate for love. And a Queen, longing for children. I wonder... what do these have in common?

What if Mt.Ebbot was in Inkwell Isle 3

Frisk and Susie are left reeling from their adventures in the Dark World, but there's no time to take a deep breath. As the Knight blows another fountain open, Frisk and Susie, along with little sister Tina, Berdly and Noelle, must seal it and stop an "evil" queen from taking over. And who is the man beckoning from Frisk's dreams, the one who speaks in hands?(MAJOR UPDATE TO Ch 13)

After waking up in the body of the protagonist of Undertale. The newly named Frisk has to find a way to deal with the consequences of actions he doesn't even remember taking. And find a way to not only save the underground, but also himself.

After freeing the monsters from the Underground what's next for young Frisk? Well, there's always the world's most popular trading card game Duel Monsters. With a deck based off of her adventures it's time for the monster ambassador to show everyone what she's made of. Though with dark forces around every corner, she'll need to remember one thing, always stay determined.

Time. Space. Reality. It's more than a linear path. Far from the Remnant you know, there are infinite others, each only a fraction different. Here, we see the results of an astronomical fluke. One that granted a child the powers of the most powerful Monster who ever lived. I'd say more, but you know what they say. It's rude to talk about people who are listening.

It's midnight in Castletown, and Frisk and Ralsei are asleep on the couch, using Susie as a pillow/teddy bear. Susie finds herself not minding. Just a little drabble set in my Hopes, Dreams, And DELTARUNE universe, sometime after the second book, though it can be read alone.

Zane dies to the overlord but his afterlife is not exactly the Departed Realm. He winds up in the Underground and quickly makes friends with most of our main characters. Of course, everyone's favorite TV personality finds himself falling hard for the new bot in town. Drama and Romance ensues, but no bloodshed. When Frisk Falls the Underground won't look the same. Crossposted on AO3

(This is a work in progress. I own nothing. Sonic is owned by SEGA, and Undertale is a product of Toby Fox.) When a blue hedgehog that can go faster than the speed of sound and a small child fall into a mountain… they will find something quite unexpected… This is a version of the Pacifist Route with Sonic in it. I will upload infrequently. Review if you enjoy!

25 years after the pacifist route today was Firsk’s 25th birthday and Toriel was going to head to the grocery store but she never came back and Firsk was on her way to find her but what she stumble upon was a old wooden workshop that seemed abandoned for centuries...

When Eddy's scam fails again, the Eds and another kid must work together to escape (or save) the underground. Will they survive? Will they make friends? Read and find out. Ed, Edd, n Eddy by Danny Antonucci. Undertale by Toby Fox

Who knew dying could offer new possibilities to monsters? Or more like a second chance like humans have? Now, it sounds cool if only it wasn't for the fact that I have been transported to Hell... as a Human itself. And why is this other smiler so interested in me? Oh well, at least it's a beautiful day outside.

Omori had been repeating the same adventure for two whole years now. Some people might think Omori would hate how repetitive it all was, but they would be wrong. Omori loved the repetitive nature of his life since it made his job so much easier. So that’s why Omori was annoyed by the fact he fell down a mountain filled with monsters instead of going on his usual adventure

Richter's past few years were a living hell for him. So, when he got the chance to redeem himself by killing Shaft and Dracula for the second time, he gladly took it. Too bad a Belmont's life is an unlucky one. In the end, he found himself in a completely different world of monsters; one where they weren't constantly attacking him. Good for a dying man like himself, he guessed.