Adventure Time is set in the post-apocalyptic Land of Ooo, which was ravaged by a cataclysmic event known as the "Mushroom War"; a nuclear war that destroyed civilization a thousand years before the series' events. It follows the story of Finn Mertens; a young heroic boy, and his best friend and adoptive older brother Jake; a talking yellow dog that has the ability to stretch into any shape he desires. Together, they go on many adventures together; slaying evil creatures and hanging out with friends, such as Princess Bubblegum (who is the ruler of a kingdom she created from scratch known as The Candy Kingdom) and Marceline, The Vampire Queen.