When does Adventure Time return?

Adventure Time is an American animated fantasy television series. It follows the adventures of a boy named Finn the Human and his best friend and adoptive brother Jake the Dog. Finn and Jake live in the post-apocalyptic Land of Ooo, where they interact with Princess Bubblegum, the Ice King, Marceline the Vampire Queen, BMO, and others. Pendleton Ward's creation is based on his 2007 short film that aired on Nicktoons as a pilot on Frederator's Random! Cartoons. The series drew inspiration from the fantasy role-playing game Dungeons & Dragons and video games.
Adventure Time follows the adventures of Finn the Human (voiced by Jeremy Shada), and his best friend and adoptive brother Jake the Dog (John DiMaggio), who has magical powers to change shape and size at will. Finn and Jake live in the post-apocalyptic Land of Ooo, which was ravaged by a cataclysmic event known as the "Mushroom War"