J.G. Quintel Mordecai , Hi-Five Ghost Director, Voice, Screenwriter Mark Hamill Skips Voice David Koechner Kevin Voice Jason Mantzoukas Randall Voice Sam Marin Benson , Pops , Muscle Man Voice William Salyers Rigby Voice Roger Craig Smith Frank Smith Voice Ryan Slater Producer Calvin Wong Screenwriter Mike Roth Screenwriter Toby Jones Screenwriter Sean Szeles Screenwriter Andres Salaff Screenwriter Benton Connor Screenwriter John Infantino Screenwriter Owen Dennis Screenwriter