Avengers Infinity War star Josh Brolin reveals the SURPRISING reason he played Thanos

WARNING: Spoilers ahead for Avengers Infinity War.

The actor, whose character killed half of all humanity in the Marvel blockbuster, credited Benedict Cumberbatch for persuading him to take the job.

But it had nothing to do with Cumberbatch’s work as Doctor Strange – it was actually his role in The Hobbit: The Desolation of Smaug.

“He’s crawling around like a snake and he’s snapping his tongue out, doing this incredible performance and I saw that and was like, alright, that’s the bar,” he told SiriusXM.

“This is not b*******. This is something you have to sink your teeth into — conviction, embarrassment, all that kind of stuff.”

He continued: “The critics were always talking about Marvel villains being the weak point, so you have that pressure.

“The way that people are reacting to this character as if he truly exists is kind of phenomenal.”

Brolin had also previously spoken about how Hulk star Mark Ruffalo had a hand in him weighing up whether or not to take the role.

“I said, you’d be a fool not to be in this movie,” Ruffalo recalled to Jimmy Kimmel.

And Brolin told Total Film: “At the beginning, before I said yes, I called Mark Ruffalo and I said, ‘What do you think of this?’

“He was like, ‘It’s going to be really uncomfortable in the beginning, and then you see the movie, and you’ll just be absolutely blown away by the stuff you were doing.’

“And that was then. They made huge leaps and bounds in mo-cap territory since then. There’s nothing not authentic about it.”

Brolin will be back next year for Avengers 4, which will explore the aftermath of the devastating Infinity War cliffhanger.

Avengers: Infinity War is still showing nationwide.