He may be one of the team's founding members and more often an ally than a foe, but the unstable Hank Pym has done more than enough over the years to be considered a villain of sorts to The Avengers. After all, not only is he responsible for creating the insane android Ultron, but his erratic behaviour meant that he was the first Avenger to be court martialed after slapping his wife Janet Van Dyne in a fit of temper. The Ultimate version took things quite a bit further. He was thrown off the team altogether after a much more brutal attack on The Wasp and later joined the traitorous Black Widow and her villainous band of Liberators. Creating an army of Ultrons to keep the American populace in line, this version of Hank tried to claim he was working to take them down from the inside when they were defeated, but ended up in a jail cell!
