Grey DeLisle
Mandy / Castigator (voice)
Greg Eagles
Grim / Sperg (voice)
Richard Steven Horvitz
Billy / Billy's Dad (voice)
Vanessa Marshall
Irwin / Mouse (voice)
Dee Bradley Baker
Alien Moonbeast / Alien Werewolf / Moonthing (voice)
Jeff Bennett
Alien #1 / Rat (voice)
Chris Cox
Meadowberry / Corporal / Postal Slob (voice)
Jennifer Hale
Billy's Mom / Stinky (voice)
Tom Kenny
Dr. Brainiac / Alien Pilot / Wiggly / Waiter (voice)
Mr. Lawrence
Alien #2 (voice)
Julian Stone
Sir Raven (voice)