Jeff Bennett

as Dr. Gluckman / Martian Guard #1 / President (voice)

Corey Burton

as Martian Scientist / Court Attendant / Eyes At Gate (voice)

Kathryn Fiore

as Peep / Press Girl (voice)

Brad Garrett

as Commander Bristle / Martian Guard #3 (voice)

Jess Harnell

as Major Buzz Blister / Martian General / Worker #3 (voice)

Tom Kenny

as Grob / Gardener #1 / Martian Guard #2 (voice)

Bill Kopp

as Tom / Press Guy #1 (voice)

Rob Paulsen

as Computer / Worker #1 / Worker #2 (voice)

Frank Welker

as Spike (voice)

Billy West

as Major Biff Buzzard / King Thingg / Gardener #2 (voice)