Unknown who he really is, the Joker in his sycopathic form by deceased Heath Ledger causes most problems to Batman. He was voiced by Hoser76 in Nightwing Begins and Robin's Birthday. He was voiced by WAstEDxLaMA in Lego Batman and Indiana Jones 3 and Keshen8 the rest. He usually has a teammate. He was the main antagonist in Lego Batman and Indiana Jones 3, Nightwing Begins, Robin's Birthday, Robin's Babysitter, Lego Batman and Spider-Man 1 and 2, and in Joker watches the Hills, along with Dr. Harleen Quinzel (Harley Quinn). And he joined Lex Luthor with others in Lego Batman and Superman .