Clay Enos / © DC Comics / Warner Bros. 1 / 7
Clay Enos / © DC Comics / Warner Bros. 1 / 7

Don't for a second believe that Jared Leto didn't know what he was getting involved in when he took on the role of The Joker. He knew he had some big shoes to fill for his part in "Suicide Squad," a role perfected by the late Heath Ledger.

"Heath did an impeccable, perfect performance as the Joker. It's one of the best performances ever in cinema. I had met Heath before. I didn't know him well, but he was a beautiful person," Jared told Rolling Stone for its cover story.

Heath went on to posthumously win an Oscar for his portrayal of The Joker in "The Dark Knight."

Jared told the magazine he felt that it was OK to play the iconic character because it had been done before by other actors over the years.

"I think had it only been portrayed by Heath and it was never a comic book, maybe I would have felt that would be inappropriate," Jared said. "But I thought that given the history, it was OK. The good thing about other people having done this is that you know what direction not to head in."

Jared took the role very seriously and remained in the character throughout most of the filming, even sending his costars vile "gifts."

"The Joker, he did some bad things," Viola Davis, who plays the sinister Amanda Waller in the movie, told Vanity Fair. "He had a henchman who would come into the rehearsal room and the henchman came in with a dead pig and plopped it on the table and then walked out, and that was our introduction into Jared Leto."

One of the most savage and disturbing "gifts" was saved for Margot Robbie, who played Harley Quinn. Jared sent her a package of a black rat.

"It was still alive in a box," Viola said. "She screamed and then she kept it."

That's just the kind of thing The Joker does.

"The Joker is incredibly comfortable with acts of violence," Jared told Rolling Stone. "I was watching real violence, consuming that. There's a lot you can learn from seeing it. Not every act of violence is committed with frenzy, either. I remember learning that. People can be calm. They've made their choice and go and do something, and it's not in a frenzy. It's methodical and sometimes even hypnotic and deliberate."