It has been a few months since the defeat of the evil Storm King. However, panic sets in as Tempest has visions of the evil tyrant conquering Equestria, not helped by the disappearance of his stony remains confirming her fears of his return.

Fearing his revenge, Twilight and the Princesses summon a champion to help them in their time of need... and he's an optimistic yellow sponge who lives in a pineapple under the sea.

Look out, Storm King and Equestria, get ready for...

SPONGEBOB SQUAREPANTS!!!!!

Inspired by the SpongeBob/MLP crossover duology by yodajax10

The Nightmare Forces have returned, ready for conquest. However, instead of attempting to conquer Equestria, they have decided to expand their campaign to another world altogether. Using the Crystal Mirror, the Nightmare Creatures have found themselves in a world where humanity is at constant war with titanic beasts known as Kaiju. With the Mane Six, Spike, and Princess Luna on their tails, the greatest nightmare however, may reside in someone they can't control. And his name is...

Godzilla, King of the Monsters.

It has been four years since the Rise of the Titans. While humans try to find ways to coexist with Godzilla and the newly awakened Titans, Madison Russell finds herself subjected to endless, grief-driven nightmares. One day, on the beach, Maddie encounters what appears to be a mermaid who is more than happy to help her through the grief.

An MLP/MonsterVerse crossover.

Princess Skystar has lived her entire life beneath the waves years after her people were driven into hiding by a monster known simply as "The Storm King" and given sanctuary by the undersea empire of Mu, her days spent under the tutelage of the ryu Manda and under the watchful eye of her mother, Queen Novo. One day, Skystar decides it is time to venture above the surface, after a fateful encounter with Godzilla, King of the Monsters, peaks her curiosity due to his grudge towards humankind. Upon venturing to the surface, assuming a human form, Skystar seeks to uncover the mysteries of Godzilla's hatred toward mankind as well as try to restore the kingdom her people once ruled... even if it means risking an encounter with the Storm King.

It has been a year since Korra defeated Amon and his Equalist army. However, her time of rest and relaxation is about to come to an end when she and her friends discover a portal which leads them to two different worlds; one a fantasy world ruled by sentient equines and creatures straight out of fairy tales and another where humans struggle for survival against gigantic beasts. However, Korra must form alliances if she is to stop a ruthless enemy whose eyes are set on conquering all three worlds.

The Nightmare is able to possess its victims, feeding on their memories and turning them into shells for it to take over. One pony is more than happy to give it his own memories if only to end the Nightmare's reign forever. Chances are, however, they won't sit well with it.

In the depths of the Pacific Ocean, a leviathan born from nature and reborn from human arrogance dreams. However, his dreams are interrupted by a mysterious woman with hair almost like the night sky. Why is she here? Why does it feel like they are so different but have so much in common?

Godzilla and Princess Luna

A few months after Twilight's transformation and coronation, Fluttershy finds herself in a new world, transformed into a human girl and comes across a boy named Kenji who lives in this strange new world. However, she soon discovers this new dimension is much more hostile than it seems. For in this world, humanity fights to stay alive against the Kaiju, a race of gigantic beasts capable of wiping entire cities off the face of the Earth. Even worse, as Fluttershy tries to find a way back home, her presence attracts the attention of the more malevolent Kaiju. Rated Teen for violence, mainly concerning traditional giant monster violence.

Now has a Tv Tropes page.