What happens when Finn gets sent back in time to 1942 only to land on Mordecai's doorstep?

Killer Moth is tired of being treated like a joke and wants to become more of a threat. After ending up in Ooo, he finds a swarm of giant moths that he gets under his control and decides to bring them back to Gotham in order to take over the city. Finn and Marceline return to Gotham and find out about the situation which leads them to help Batman again to stop Moth and his army.

Caillou goes to the Land of Ooo and meets Finn and Jake.

Jack Frost wakes up from a frozen sleep to a land unfamilliar to him. The Land of Ooo. Join him as he tries to find out what happened to him and as he navigates and encounters the land and its strange inhabitants. Inhabitants as strange as him, if not more. ...Definitely more. A collection of one-shots and occasionally connecting chapters.

Una nueva vida, una aparentemente de paz y tranquilidad, hasta que cierto incidente pone su nueva vida patas arriba, una nueva guerra, pero esta vez no podrá hacer nada para detenerla, su nuevo objetivo es sobrevivir al apocalipsis, nuevas aventuras, nuevos amigos, nuevos enemigos

After turning the tide of the Giant War at the cost of his friends, Gaia and Kronos send Percy hurdling through time to a place where the gods are even more hidden, creatures weirder then his, bizarre kingdoms and only one and a half humans(counting himself) are still alive.

The heroes of Oooh and their Seeker Agent friends are trying to make sense of their current situation, meanwhile Marceline may have met a potential love interest.

The Land Of Oooh is dying and Finn, Jake, Princess Bubblegum, Marceline and BMO must venture into deadly new territory to find a new home and do so with The Deadly, Dangerous and Evil Doctor Gross but does The "Good" Doctor have other Plans?

An all out crossover series with Finn and Jake and all of Ooo getting transported to Earthland meeting Natsu, Lucy, and Happy of the famous magic guild Fairy Tail. Being best bros and saving each other's side, an adventure like you've never seen before begins as Finn and Jake fight against villainous evil like Dark Guilds, Demons, Monsters, and New Evil Alliances.

Lelouch's Zero Requiem was complete and after his death, God was not done with his toy. Lelouch has been struck down into the land of Ooo now bearing a code. He will struggle and lament to find a purpose once one's greatest work has been achieved. Maybe it's his turn to play advisor to the king? Following in C.C.'s footsteps in giving no fucks he will find his new purpose.

A more light hearted My hero story instead of a dark one, what if there were heroes who had odd quirks that made them more than they seem (too many crossovers to cover here on FFN) and a certain Hero to be gets more than he bargained for when a number of women are interested in him... lemons galore inside, combat and drama heavy, but mainly a hero filled story.

A My Little Pony one-shot. It was a normal day in Ponyville, and the citizens were going about their day, that was until Dragon Lord Ember crash-landed in Sweet Apple Acres with a message: "My dad... Torch... attacked us..." Whatever is causing this great dragon's rampage, the Mane 6 and some close friends steps up to this challenge!

It was a horrible idea to trust Naruto with anything, especially teleportation seals.

This story starts out after Finn set Phoebe and Ice King against one another, and most of the princess of Ooo hold a Trial for Finn for his crimes, what will happen in the story?, find out now!, IT'S BADLANDS TIME! (All Lemon subjects shown will be 18 and up for morality sake, anything else will be skipped, plot reason in prologue 1. (Now on Hiatus/Remake in works)

Deep within in the web of the multiverse. Prismo detected the presence of a great and familiar evil. To deal with it, Prismo sent his best man for the job.

Summary:

After a devastating final battle against the remnants of the legion, the Courier wakes up in the magical land of Aaa! A bright and colorful world full of endless wonders. Yet can this world survive the courier's wrath? (Old Version)

After being friends for years, Finn and Marceline tell each other how they feel and begin dating. After messing around with magic crystals, they end up in Gotham where they meet and befriend Batman. Meanwhile, Two-Face plans to blow up half of both Gotham and Ooo so they see the world like he does. With their homes in danger, Batman teams up with Finn and Marcy to stop Two-Face.

Jake the Dog takes Finn to a Pizzaria for his birthday but what they don't know is that the Pizzaria has a "few" tricks up its shelves.

Thirtieth installation of The Voyagers. After a disastrous adventure, Finn and Jake find themselves in Equestria, populated by colourful ponies, with Finn transformed into one too! After meeting the heroes known as the Mane 6, they get to know each other better, while something stirs in the Crystal Empire. Minor crossover with Steven Universe and Transformers.

While Finn and Jake are off adventuring in other universes, who helps Ooo to deal with giants, helping people in need, and fighting the occasional robot army? The Voyagers do! In this story, we follow Huntress Wizard, Tiffany, and Bronwyn in their latest adventure filled with action, tragedy, and twists!

Ever wonder how the band of misfits dubbed Marceline and the Scream Queens started? This is the story of how four people struggling to find a place in the world came together to form the baddest band there ever was! This is the coronation of Marceline and the Scream Queens! Minor Transformers elements, don't mind it.

Twenty-ninth installation of The Voyagers. After a summons by Prismo, Finn and Jake set out to investigate the mysterious Barista, but are called to a mission once more. As if fate guided them, Finn and Jake meets The Barista on the mission, but are soon dragged into another universe by a mysterious figure? Who exactly is this mysterious Barista?

Una nueva vida, una aparentemente de paz y tranquilidad, hasta que cierto incidente pone su nueva vida patas arriba, una nueva guerra, pero esta vez no podrá hacer nada para detenerla, su nuevo objetivo es sobrevivir al apocalipsis, nuevas aventuras, nuevos amigos, nuevos enemigos y mas (Summary en proceso)

Twenty-eighth installation of The Voyagers. Finn and Jake chase a mysterious being into space in the mighty mech Ursa Kildare, but are quickly defeated, causing Jake's death... until he is resurrected by a mysterious ball of light. Will he save the Earth from this invader as an... Ultraman!