Futurama: Into the Wild Green Yonder is a 2009 American direct-to-video adult animated science fiction comedy-adventure film serving as the fourth and final Futurama film. The film was written by Ken Keeler, based on a story by Keeler and David X. Cohen, and directed by Peter Avanzino. Guest stars include Phil Hendrie, Penn Jillette, Snoop Dogg and Seth MacFarlane, who sings the theme song. In the movie, Leela becomes an outlaw when she and a group of ecologically-minded feminists attempt to save an asteroid of primitive life forms and the Violet Dwarf star from being destroyed, while Fry joins a secret society and attempts to stop a mysterious species known as the "Dark Ones" from destroying all life in the universe. The title itself is a reference to the U.S. Air Force Song, the main chorus of which describes reaching "Into the wild blue yonder". Directed by: Peter Avanzino. Story by: Ken Keeler & David X. Cohen Teleplay by .