Seth Green as The Nerd / Batman / Robin / Aquaman / Additional Voices (voice)

Breckin Meyer as Superman / Plastic Man (voice)

Alex Borstein as Wonder Woman (voice)

Nathan Fillion as Green Lantern (voice)

Matthew Senreich as The Flash / Brainiac (voice)

Jonathan Banks as Composite Superman (voice)

Alfred Molina as Lex Luthor (voice)

Giovanni Ribisi as The Joker / Two-Face (voice)

Paul Reubens as The Riddler (voice)

Adam West as 60's Batman / Bank Robber (voice)

Burt Ward as Self (voice)

Hugh Davidson as Martian Manhunter / Tran-Zar (voice)

Zeb Wells as Green Arrow / Swamp Thing (voice)

Dee Bradley Baker as Ra's al Ghul (voice)

Kevin Shinick as Narrator (voice)

Mae Whitman as Power Girl (voice)

'Weird Al' Yankovic as Rubberduck (voice)

Shooter Jennings as Mr. Banjo (singing voice)