Watch Mark Ruffalo Explain The Hulk's Role in "The Avengers"

Movie Trailers - Movies Blog

"He has an interesting thing with Black Widow, actually. And him and Tony Stark are… You know, he’s like the fallen angel version of Tony Stark. He was the renegade professor who was kind of a rebel, arrogant, kind of doing things that were unorthodox. There’s a real admiration between the two of them that’s interesting, and Tony Stark really enjoys the idea of watching this guy turn into The Hulk. So he’s nudging him in an interesting sort of way. There’s a lot of nice, fun play between the two of them."