Mark Ruffalo bases The Hulk on his ten-year-old son.

The actor portrays the famed green muscle man in the new movie Avengers Assemble, which also stars Robert Downey Jr., Samuel L. Jackson and Scarlett Johansson.

Mark opened up about his inspiration for the part, explaining he didn't have to look that far from home.

"I was channelling my ten-year-old son, who I dedicate my performance to," he laughed.

"It's that horrible moment in a child's life when the world expects a certain kind of behaviour from [them], but [they] can't quite hold it together and [they] break out in rage and it's Hulk-like. So, I used him quite a bit for that character."

Many of the stars of the superhero movie have discussed their costumes in the past, with Chris Hemsworth explaining he was too big for his Thor suit.

Mark didn't have such a fantastic outfit as he had to don a motion capture suit, which he wishes had been more flattering.

"I was wearing a frumpy little, like, linen thrift store suit and they were all in their superhero costumes looking very, very full," he is quoted as saying by Access Hollywood.

"It was showing everything and not showing enough - if you know what I mean!"