A hero published by Marvel Comics. Ant-Man first appeared in a story called "The Man in the Ant Hill" in Tales to Astonish #27 in 1962.

Henry Pym was a scientist who a subatomic particle that when used in a particular way reduced the physical mass of an object. Naming these particles "Pym particles," he used these on a number of adventures, eventually adopting a costumed identity as Ant Man. Pym's costume included a cybernetic helmet that allowed him to communicate with ants and get them to do his bidding.

During this time, Pym met the daughter of one of his colleages, a man Van Dyne. His daughter, Janet, bore a striking resemblence to Pym's first wife Maria, who had been killed by revolutionaries in her home country of Bratislavia. Pym and Janet were dating when Janet's father was killed by aliens. Pym in the guise of Ant Man attempted to help and even revealed his true identity to Janet. He convinced her to join him and after undergoing a procedure created by Pym, Janet gained the ability to shrink, to grow wings which allowed her to fly, and to fire energy blasts. Janet adopted the name the Wasp and joined Pym in avenging her father.

Ant Man and the Wasp gathered with Thor and Iron Man to fight the Hulk and at the suggestion of the Wasp, decided to fight together as the Avengers. After adventuring for a while, Pym decided to use the Pym particles to grow rather than shrink and adopted a new identity as Giant-Man. Not long afterward, Pym proposed to Van Dyne and the two left the team to get married.

The two returned to the team and Pym continued to adventure as Giant-Man for a time, but later created his third costumed identity of Goliath. During his time as Goliath, Pym experienced a point at which he became stuck at 12 feet tall.

Though an accomplished scientist, Pym has had a number of issues over the years. One of the earliest involved his creation of a robot called Ultron. Ultron was created with advanced intelligence, but ended up hating its creator. Soon after it was activated, Ultron ended up capturing Pym and wiping his memory of Ultron. Ultron eventually returned and battled both Pym but also his teammates in the Avengers.

Pym has also battled a number of mental issues over the years. The first was triggered by a lab accident that caused Pym to create a fourth costumed identity Yellowjacket. In his new identity, Pym kidnapped Van Dyne and forced her to marry him. When confronted by his fellow Avengers, Pym came to his senses, but continued to adventure as Yellowjacket.

Pym continued to slide, becoming increasingly unsure of himself. He struck Van Dyne in a domestic dispute and later attacked an opponent who had surrendered to the Avengers. His actions caused his fellow heroes to decide to "court martial" Pym. Pym decided to prove his worth to the team by creating a robot to attack the Avengers, but containing a failsafe that would only allow him to defeat the threat. However, during the battle, Pym's failsafe did not work and his plan was revealed. The Avengers were able to defeat the robot, but Pym was kicked out in disgrace and Van Dyne filed for divorce.

Soon after this, one of Pym's enemies Egghead captured him and forced him to aid his group the Masters of Evil to attack the Avengers, threatening to harm an innocent woman if he did not. Pym aided Egghead, but eventually was able to create a device that defeated not only Egghead, but also the other members of this alliance of villains. Pym then went into seculsion for a while.

Pym worked with the West Coast Avengers for a time, but he continued to be more and more depressed about his situation in life. Pym contemplated suicide, but the heroine Firebird convinced him of the sanctity of life and of the value of his life. Pym returned to adventuring, forgoing a costume, instead choosing to wear either a red jumpsuit or in some cases, dressing as a Doctor Who wanna-be. In this latest incarnation, Pym used Pym particles to shrink and grow objects to use in adventures, everything from a baseball bat to rayguns.

Pym and Van Dyne began to work together again and eventually they began to become romantically involved again. Pym began to adventure again as Goliath after he lost the ability to shrink again. He and the other other Avengers seemingly sacrificed themselves to stop the threat of Onslaught, but were actually shunted to a pocket dimension for a time. Upon their return, Pym found that he could again both shrink and grow.

While fighting Kulan Gath, an ancient wizard, Pym was mystically split into two beings, Henry Pym and Yellowjacket. Yellowjacket imprisioned Pym and took his place for a time, but soon the spell began to weaken and the two were forced to rejoin. Pym eventually came to terms with both sides of his nature and has again began to adventure as Yellowjacket, in a bid to redeem this part of himself.