What was the name of an animated American television series which is set in a post-apocalyptic world, with an episode named Reign of Gunters?
Adventure Time (season 4): The fourth season of "Adventure Time", an American animated television series created by Pendleton Ward, premiered on Cartoon Network on April 2, 2012 and concluded on October 22, 2012. Adventure Time (season 4):  Finn and Jake live in the post-apocalyptic Land of Ooo, where they interact with the other main characters of the show: Princess Bubblegum, The Ice King, Marceline the Vampire Queen, Lumpy Space Princess, BMO, and Flame Princess.
i don't know