Guest Stars Clancy Brown voices Lex Luthor William Atherton voices Dr. Destiny / John Dee Peri Gilpin voices Volcana / Claire Selton Mark Hamill voices Solomon Grundy Mark Rolston voices Firefly / Garfield Lynns Fairuza Balk voices Penny Dee Nicholas Guest voices Luminus / Edward Lytener Nicholas Guest voices Dr. Bill Brooks Richard McGonagle voices Warden Uncredited Carl Lumbly voices Inmate Michael Rosenbaum voices Guard Maria Canals-Barrera voices Cop Mark Hamill voices The Joker Richard McGonagle voices Rick Jose Yenque voices Copperhead