Dwayne Johnson's dramatic physical transformation is for the role of a lifetime: a 70-year old who is best friends with a chicken

After playing an MMA fighter in Benny Safdie's sports biopic The Smashing Machine, Dwayne 'The Rock' Johnson is reteaming with the director in his upcoming movie Lizard Music, in which the star will take on the role of a 70-year-old man… who is best friends with a chicken.

"Benny pitched me this after. And after about 45 minutes, this pitch ended and I said, 'I am your Chicken Man,'" said Johnson at a career retrospective talk at the Toronto International Film Festival, via Variety. According to Johnson, the film will see him take on the role of a "whimsical, eccentric 70-something-year-old" known as Chicken Man.

The upcoming movie is based on the 1976 novel of the same name by author Daniel Pinkwater. The Lizard Music book follows a boy named Victor who befriends an eccentric older gentleman called Chicken Man, who understands the lizards' music. Together, the pair journey to the lizards’ floating island.

The new role explains Johnson's recent physical transformation. Fans were shocked to see the ex-wrestler had shed so much weight after seriously bulking up for Safdie's new movie The Smashing Machine, which stars Johnson as UFC fighter Mark Kerr. However, Johnson says he still has "a long ways to go" before he reaches peak Chicken Man physique.

"I’m so excited to get a chance to hopefully transform again like I was able to do in 'Smashing Machine,'" said Johnson at the event. "[It means] eating less chicken."

Although the upcoming project seems a little offbeat for Johnson, the star has recently shown interest in taking on more peculiar and gritty roles after feeling "pigeonholed" by Hollywood. "I have wanted this for a long time," said Johnson at the Venice Film Festival after admitting he had a "burning desire" to be more than a blockbuster star. "When you're in Hollywood, as we all know, it [becomes] about box office… It can push you into a corner and category."

Lizard Music does not yet have a release date. For more, check out our list of the most exciting upcoming movies and movie release dates.