Ant-Man

Ant Man is a Marvel superhero, who, like Iron Man has a powersuit. He worked with SHIELD. His true identity is Hank Pym, a scientist who invented a substance which gives him the power to change his size. He later retired from being Ant Man, and was successed by Scott Lang and Eric O'Grady.

Background Information
After Hank retired, Ant Man has had many changes.

Hank Pym
Dr. Henry "Hank" Pym was the original Ant Man. The name was chosen by the fact that his most common size was about the size of an ant, and that he could control ants with his helmet. Revealing this secret to his girlfriend, she became the Wasp (using the same technology as Hank did to shrink herself), although she can fly. They were the first two members of the original Avengers.

After he retired Ant Man, he took the identity of other heroes, including Giant-Man, Goliath, Yellowjacket, and the Wasp, after his girlfriend Janet Van Dyne died.

Scott Lang
Scott was a thief, who first became Ant Man when he stole Hank's suit to save his daughter, Cassie, who had a heart condition. Seeing as how Hank's technology had saved his daughter, he took up heroing as the new Ant Man. He would occasionally work with the Fantastic Four, and later became a member of the Avengers. He was eventually killed by the Scarlet Witch, Vision, and Hawkeye, although Cassie became the heroine known as Stature, a member of both The Young Avengers, and The Initiative.

Eric O'Grady
Although he was a SHIELD agent, Eric did not use the Ant Man technology for good. He saw it as simply a way to impress women.

Trivia

 * There are no current trivia available on this topic, as of the moment.