Season 1, Episode 8: "Some Assembly Required"

"Some Assembly Required" - The Avengers have assembled, but calling themselves a team is different than BEING one, especially when you've got the Hulk as a member. As Iron Man introduces the Avengers to Avengers Mansion, the Hulk is ready to smash them all... with a little magical push from the Enchantress. The Avengers may be over before they start as they take on one of their own.