When does Adventure Time return?

Adventure Time is an American fantasy animated television series. The series 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, BMO and others. Adventure Time has received universal acclaim from critics, with much praise for its originality and worldbuilding. It ended its eight-year run on September 3, 2018, after the airing of its tenth season.
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"