The 44-year-old actor is set to take on the iconic role for the first time this summer as he stars in the eagerly anticipated "Suicide Squad," reported Entertainment Weekly.
"You're kind of walking upon hallowed ground, and it deserves the very best that you can do. It takes over your life and that's what I needed to do for myself.
"You don't know what the Joker is going to do next; you never do. It was intoxicating to have no rules."
The film also stars Will Smith, Margot Robbie, Viola Davis, and Joel Kinnaman.