Ant Man (real name Henry "Hank" Pym) is a super-scientist from the Marvel Universe whose invention, Pym Particles, allow him to grow larger or smaller at will. A pacifist, Ant Man prefers science to superheroing. However, being a founding member of the Avengers (one who was tragically left out of the movie) puts him in a lot of situations where a peaceful conclusion just isn't possible. Because of this, he has left the Avengers many times, only to come back later on. A bit of a schizophrenic, Pym has assumed many different identities, some of which are Giant-man, Goliath, and Yellowjacket. In fact, as Yellowjacket,Hank claimed that he was a totally different person who had murdered Henry Pym. During this period, he became more and more hysterical under the stress of being a superhero, which led to him lashing out physically at his wife, Janet VanDyne. Though he apologized pretty much immediately after, and he and Janet have since reconciled and remarried (several times), this incident continues to paint his characterization and personality to this day.

Janet has since been killed off, because according to the head of Marvel (who I refuse to name), Ant Man just wasn't "interesting" enough with a wife.