When it comes to bringing a group of famous superheroes together to fight on the same team, it doesn't always go very swimmingly -- especially for Iron Man, Thor and Captain America, whose initial meeting in The Avengers doesn't exactly begin with a nice "hello" and a handshake. Here, Iron Man welcomes Thor back to earth by engaging him in battle in the middle of the woods. Let's hope one of them survives because they'll be needed later in the film, which is set to rock your socks off this May 4th.