Kristen Stewart loves the "energy" behind an online campaign for her to play the Joker in the 'Batman' franchise.

Kristen Stewart

Kristen Stewart

The 31-year-old actress' ex-boyfriend Robert Pattison will play the central role in 'The Batman', and Kristen is aware of the campaign to cast her alongside her former 'Twilight' co-star.

Kristen - who played Bella Swan in the money-spinning film franchise - said: "I love the energy behind that. It’s really been done so well. I feel like, maybe, we don’t traipse over, but I love that gusto.

"Let’s figure something else out. I’m totally down to play a freaky, scary person."

Asked whether her initial response was a complete "no", Kristen told 'Entertainment Tonight': "Not ‘no,’ but not the most stoked I’ve ever been. Let’s do something new."

Kristen and Robert were involved in a four-year romance until 2012, after they appeared together in the 'Twilight' films.

The Hollywood duo were one of the most high-profile couples in the world at the time, but their relationship fell apart after Kristen was spotted kissing film director Rupert Sanders.

Meanwhile, Robert previously admitted he was thrilled to have been cast as Batman in the upcoming film.

The 35-year-old actor confessed that playing the iconic character felt a bit surreal.

Robert - who is following in the footsteps of actors such as Christian Bale and Ben Affleck - said: "It's a strange feeling.

"I had moments when I was shooting and just I'd catch a glimpse of myself and think 'Wait - am I actually doing this? This is crazy!' But it's been really fun and really exciting so far. But it's a very special feeling - it's been an honour."