We've read numerous accounts of how Jared Leto threw himself into the role of The Joker, sending a live rat to "Suicide Squad" co-star Margot Robbie and a dead hog to the entire cast -- and that was only the beginning of the weirdness. Needless to say, the Oscar winner was quite serious about the Clown Prince of Crime.

"You're kind of walking upon hallowed ground, and it deserves the very best that you can do," he told Entertainment Weekly, referring to a character who's been played by the likes of Cesar Romero, Jack Nicholson, Mark Hamill and Heath Ledger. "It takes over your life and that's what I needed to do for myself."

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Even director David Ayer admits that Leto was "scary on set." However, it was all merely part of the actor's process, which included meeting with psychiatrists and "their most damaged patients."

"You don't know what the Joker is going to do next; you never do," Leto said. "It was intoxicating to have no rules."

The actor, who won an Academy Award for his performance in 2013's "Dallas Buyers Club," has referred to The Joker as "a role of a lifetime."

Opening Aug. 5, "Suicide Squad" also stars Will Smith, Margot Robbie, Joel Kinnaman, Viola Davis, Jai Courtney, Jay Hernandez, Adewale Akinnuoye-Agbaje, Ike Barinholtz, Scott Eastwood and Cara Delevingne.