Robert Pattinson. Picture: Bang Showbiz

"The Batman" star Robert Pattinson expected an even harsher backlash to his casting as the Caped Crusader.

The 33-year-old actor will don the famous cowl when he plays the Caped Crusader in screenwriter Matt Reeves' upcoming comic book blockbuster, and while some fans have voiced their disapproval of the casting - including a Charge.org petition to have him removed from the role - he insisted it could have been worse.

Speaking to Variety, he said: "To be honest, it was less vitriolic than I was expecting. It's much more fun when you're an underdog. There's no expectation of you."

Rather than worrying about public reaction, Pattinson revealed he was actually more "upset" about the casting news leaking before an official announcement.

He admitted: "When that thing leaked, I was f***ing furious. Everyone was so upset. Everyone was panicking from my team. I sort of thought that had blown up the whole thing."

The "Twilight" star's big screen debut as Batman is set to be released in 2021, and he admitted putting on the iconic costume for his final audition was "quite transformative".

He added: "It's maybe the craziest thing I've ever done in terms of movie stuff. I put it on. I remember saying to Matt, 'It does feel quite transformative!' He was like, 'I would hope it does! You're literally in the Batsuit.' "

Despite the backlash, "The Batman" team has thrown its support behind Pattinson, with producer Michael E Uslan asking people "wait till they see the movie" before they prejudge.

He said: "My position is this: trust the filmmaker and give the filmmaker, and the filmmaker's vision, the benefit of the doubt. Then wait 'til you see the movie.

"And then once you see the movie, judge the hell out of it. But I think that's really the formula going forward."