Trent/The Gray Ghost [ edit ] Main antagonists (l-r) Mr. Freeze , Poison Ivy , the Penguin , the Joker , Harley Quinn , the Mad Hatter , the Riddler , Catwoman (and Isis), and Two-Face . Voice Actor Role Mark Hamill The Joker Paul Williams Oswald Chesterfield Cobblepot/The Penguin Adrienne Barbeau