Season 4 featured a redesign to Bruce Wayne, with a more square facial and chin structure, making him reminiscent of the DC animated universe Batman design. Dick Grayson as Robin (voiced by Evan Sabara) was introduced into the show, as the Teen Titans animated series had been cancelled early in the year before this season started. Batgirl is now part of the team and found out the secret identities of both The Batman and Robin, and Lucius Fox (voiced by Louis Gossett Jr.) is introduced in the season finale. Also, Robin and Batgirl begin a sibling-like rivalry. More villains appeared, such as Tony Zucco (voiced by Mark Hamill, who voiced the Joker in the DC animated universe), Killer Moth (voiced by Jeff Bennett), Black Mask (voiced by James Remar), Rumor (voiced by Ron Perlman), Everywhere Man (voiced by Brandon Routh), Harley Quinn (voiced by Hynden Walch), Francis Grey (voiced by Dave Foley), and the Basil Karlo version of Clayface (voiced by Wallace Langham in the first appearance, Lex Lang in the second appearance). In his final appearance, Ethan Bennett, the first Clayface, is redeemed and cured of his condition.