Co Starring Arleen Sorkin voices Harley Quinn Mark Hamill voices The Joker Paul Williams voices Penguin Jeff Bennett voices The Creeper / Jack Ryder Diane Pershing voices Poison Ivy Sam McMurray voices Ernie Maggie Wheeler voices Fake Harley Allan Rich voices King Barlowe John Garry voices Joker's Lawyer Uncredited Jeff Bennett voices Barlowe's Bodyguard Tara Strong voices Software Expo Woman Maggie Wheeler voices Landlady Loren Lester voices Arkham Guard John Garry voices Perry