After Marvel revealed the very first trailer for The Avengers: Age of Ultron a special guest came onto the stage at Hall H at the San Diego Comic-Con. It was none other than Josh Brolin (Gangster Squad, Oldboy) with a rubber Infinity Gauntlet. Showing the fans and the world....Thanos is here. This was Marvel's first announcement that Brolin would be the big baddie Thanos after his first cameo back in The Avengers and then Guardians of the Galaxy:
Josh Brolin can be seen battling The Avengers in The Avengers III
