I have a theory. Adventure Time, Clarence, Steven Universe, Bravest Warrior's, and The Marvelous Mis-adventure's of Flapjack exists within the same universe!!!

CLARENCE

Clarence take's place before the great mushroom war. This show was also created by Skyler Page, the former storybord artist for Adventure Time. On one episode, titled "Panties", Clarence is thinking in his mind that he is in a candy land. He also think's a jar of candy is talking to him. Clarence did not know this, but these were vision's of living candy living in the Candy Kingdom!

THE MARVELOUS MIS-ADVENTURE'S OF FLAPJACK

The mushroom war finally started. Large group's of human's scatter to find shelter and refuge.

One of these shelter's were in the middle of the ocean. Stormalong Harbor from Flapjack! The many sea monster's and other monster's were created from the radiation from the nuclear bomb's used in the war. Candied Island is actually the Candy Kingdom. Peppermint Larry visited Candy Kingdom. He met Princess Bubblegum and he fell in love. But he had to leave home to Stormalong. But when he got home he made Candy Wife, 'cause she reminded him of the princess.

STEVEN UNIVERSE

Another grope of human's retreated to the Cook Island's. A few year's later, the human's built Beach City. The Floating Gem's, 3 small island's off the coast of Ooo (from Adventure time), are associated with the Crystal Gem's, maybe even the birth place of a few gem's. The Cintedel from Adventure Time is an interdimentional prison. It is made entirely made out of pink Crystal's. This was a prison owned by Rose Quartz, Steven's mom.

BRAVEST WARRIOR'S

The biggest grope of human's left to Mars!! The human's befriended the alien's, and now live in harmony. But they did not reproduce fast enough. This is why there are not many human's on Bravest Warrior's. Also, when Chris tried to imagine Earth, there was a large crater in it. The same crater is seen in Adventure Time! The human's are not sure how much radiation is on the Earth's surface. So they stayed in space.