Co Starring Robert Costanzo voices Detective Bullock Bob Hastings voices Commissioner Gordon Arleen Sorkin voices Harley Quinn Mark Hamill voices The Joker Diane Pershing voices Poison Ivy Marilu Henner voices Veronica Vreeland Ron Perlman voices Clayface Liane Schirmer voices Officer Renee Montoya Tress MacNeille voices Little Boy Corey Burton voices Uniformed Cop Rachel Davey voices Mary McSweeney Uncredited Ron Perlman voices Cur, Lar, Mo Ron Perlman voices Carol Singer Robert Costanzo voices Carol Singer Tress MacNeille voices DIspatch Corey Burton voices Joe Corey Burton voices Sports Commentator