After a high school lab experiment goes horribly wrong, Mordecai and Rigby must go back in time to battle an evil volleyball coach in order to save the universe — and their friendship.
Mordecai / Hi-Five Ghost (voice)
J.G. Quintel
Rigby (voice)
William Salyers
Benson / Pops / Muscle Man (voice)
Sam Marin
Skips (voice)
Mark Hamill
Eileen (voice)
Minty Lewis
Mr. Ross (voice)
Jason Mantzoukas
Principal Dean (voice)
David Koechner
Jablonski / Frank Smith / Fast Food Guy (voice)
Roger Craig Smith
Ship Computer / Rigby's Mom (voice)
Ali Hillis
Gene (voice)
Kurtwood Smith
Sherm (voice)
Eddie Pepitone
Gino (voice)
Paul F. Tompkins
Father Time / Security Guard / Additional Voices (voice)
Fred Tatasciore
Techmo / Brit / Commander / TV Game (voice)
Steve Blum
Margaret (voice)
Janie Haddad Tompkins