Jack Black

as Dethklok's Original Manager / Fat Fan (voice)

Mark Hamill

as Mr. Salacia / Senator Stampingston (voice)

Mike Keneally

as Toki Wartooth (voice)

Malcolm McDowell

as Vater Orlagg (voice)

Brendon Small

as Nathan Explosion / Skwisgaar Skwigelf / Pickles / William Murderface / Young Toki Wartooth / Charles Offdensen / Ishnifus Meaddle / Edgar Jomfru / Eric Jomfru / Magnus Hammersmith / Dr. Rockzo (voice)

Victor Brandt

as General Crozier (voice)

Raya Yarbrough

as Abigail Remeltindrinc / Old Groupie (voice)

Ulrich Wild

as Bald Fan (voice) (uncredited)

George Fisher

as Metal Masked Assassin (voice)