Ruffalo has had Hulk rage moments

Mark Ruffalo has admitted there is a bit of an Incredible Hulk temper lurking underneath his peaceful demeanour.

The actor - who plays brilliant scientist Bruce Banner and his big, green alter ego, the Hulk, in superhero tale Avengers Assemble - said there was a time when he had anger issues.

"When I was a young actor, if you came to my apartment, you would have seen pictures and photos hung in the most bizarre places, where they were covering holes in the wall from auditions that I didn't get or slights that I felt I had suffered, where things were thrown, cups were thrown at the walls," he said.

"I'm no stranger to that kind of anger and rage.

"But over time, I've, like a rock that's spent many times being tumbled around in the sea, I've sort of gotten the edges polished off of me. I'm not fighting the same fights that I was back then, the same demons."

The 44-year-old also talked about his transformation to play the character, saying it was amazing the way that the Hulk's face even resembled his own.

"It's creepy, I have to say," he said. "It's exactly what we wanted it to be like. Even my chest hair, the grey in my hair. Wow. It's pretty amazing, but it's a little shocking."