Ant-Man is the codename of three characters in the Marvel Universe: Hank Pym, Scott Lang, and Eric O'Grady.Dr. Henry "Hank" PymThe original Ant-Man, Dr. Henry "Hank" Pym was created by Stan Lee, Larry Lieber, and Jack Kirby. Making his Silver Age debut in Tales to Astonish #27 (January, 1962), Hank Pym was an ordinary, but brilliant biochemist. Happily married to Maria Trovaya, a political refugee, Hank was devastated when she was murdered on a trip to Hungary. Her death led to Hank's first mental breakdown, one of his defining attributes in later years. After recovering, Hank threw himself into his work, leading to the creation of a rare group of subatomic particles. Pym then uses the particles to create two serums: one that shrinks objects and one that makes them larger. Testing the first serum on himself, Pym shrinks to insect size for the first time but is unable to reverse the procedure. Now trapped in a nearby anthill, Pym nearly drowns in honey before being rescued by a friendly ant. The new friends fend off an attack by other ants looking for an easy meal before Pym makes it back to his lab. Using the second serum to return to normal size, Pym recognizes the danger of his discovery and decides to destroy the serums before they can do more harm.Realizing that he was destroying a breakthrough, Hank recreated his serums a few weeks later. Inspired by his experience in the anthill, Pym uses the shrinking serum to become the superhero Ant-Man in Tales to Astonish #35 (September, 1962). He would pick up a partner a few issues later in the form of Janet van Dyne, a young socialite who closely resembled his dead wife. With her father dead thanks to the arrival of the creature from Kosmos, Janet volunteers to undergo genetic alteration at the hands of Pym to become "The Wasp". Together, the heroes defeat the Kosmosian and become partners. Later, the duo would join Iron Man and Thor in battle against the Hulk until the heroes realize that they've been manipulated by Loki, the God of Mischief. Banding together, the heroes defeat Loki and officially become The Avengers.Scott LangThe second Ant-Man, Scott Lang was created by David Michelinie and John Byrne. Lang first appeared in Avengers #181 (March, 1979). He assumed the Ant-Man identity Marvel Premiere #47 (April, 1979).An electronics expert on the brink of poverty, Scott Lang turned to crime to support his family. A poor criminal, Lang is arrested during a botched robbery and sent to prison. Studying electronics in his free time, Lang earns himself a job offer from Stark International after being paroled early for good behavior.Resuming his work in the field of electronics, Lang's life appears to be on the upswing until his daughter, Cassie, is diagnosed with a congenital heart condition. The only person capable of curing her condition was Dr. Erica Sondheim, but she was being held prisoner at Cross Technological Enterprises (CTE). Desperate, Lang breaks into Hank Pym's home and steals some of Ant-Man's equipment so he can confront the villain Darren Cross, the owner of CTE. Engaging the villain as "Ant-Man", Lang successfully uses his new powers to defeat Cross and rescue Dr. Sondheim.Prepared to return to prison for theft, Lang is shocked when Hank Pym allows him to keep the stolen Ant-Man equipment. Recognizing Lang's true nature, Pym's only condition was that Scott must use the Ant-Man persona to uphold the law. Relieved, Scott receives more good news from Dr. Sondheim: Cassie's heart condition was successfully cured.Eric O'GradyThe third Ant-Man, Eric O'Grady was created by Robert Kirkman and Phil Hester. He first appeared in 'The Irredeemable Ant-Man #1'' (September, 2006). Introduced as a low-level S.H.I.E.L.D. agent assigned to the Helicarrier, Eric O'Grady was the kind of guy who'd lie, cheat, and steal his way through life. Fortune struck one day when O'Grady and his best friend, Chris McCarthy, are put on guard duty outside Dr. Hank Pym's lab after Wolverine's dead body is brought aboard. Brainwashed by HYDRA, Wolverine is revived and starts killing everyone in sight. Panicking, O'Grady knocks Dr. Pym unconscious when the alarms start blaring. Messing around with the prototype Ant-Man suit in Hank's lab, Chris becomes trapped at insect size, causing O'Grady to panic again as HYDRA launches a full-scale attack on the helicarrier. Lost in the Helicarrier, Chris returns to full size only to be shot in the head. Looking for a place to hide, O'Grady stumbles across Chris's dead body and steals the Ant-Man suit. The Helicarrier sustains heavy damage during the attack, eventually crash landing in Arkansas. Surviving the crash, O'Grady retains his job as S.H.I.E.L.D agent during the day while experimenting with the Ant-Man suit at night.Comics
Ant-Man: An upcoming Marvel Cinematic Universe film to be directed by Edgar Wright which is set to be released July 2015. According to Wright, both Hank Pym and Scott Lang will be in the film. Paul Rudd has been cast to play as Ant-Man, though no confirmation yet on which Ant-Man would he played.
The Avengers: Earth's Mightiest Heroes: The first cartoon to include more than one Ant-Man, as Hank Pym passes the title to Scott Lang in season two, and also the first cartoon in which Hank Pym becomes Yellowjacket.
Hand Blast: Each Ant-Man has blasters built into his gloves allowing him to fire bio-electric energy blasts from his hands.
Legacy Character: Scott Lang and Eric O'Grady are legacy characters to Hank Pym; Stature (Scott's daughter, Cassie) is this to Scott and Hank; and Hank's own Wasp identity made him a legacy character to his own former sidekick.
Made of Iron: Growing to giant size increases Ant-Man's density, giving him greater durability.
My Suit Is Also Super: Each Ant-Man suit was exposed to Pym Particles, allowing it to change size with the hero that uses it.
Size Shifter: Hank Pym initially required doses of Pym Particles in order to change size, requiring him to carry special pills or gas canisters. Later, Hank's body would start to generate Pym Particles on its own, allowing him to change size at will.
Speaks Fluent Animal: Each Ant-Man has a cybernetic helmet that allows him to communicate with insects.
Super Strength: Only available in giant form. A portion of the strength goes to supporting Ant-Man's body, leading to diminishing returns if he grows too large.
Ascended Extra: Hank's first appearance in Tales to Astonish #27 was a seven page story where as a scientist, he just tests his shrinking experiments on himself and runs afoul of some ants. "The Man in the Ant Hill" was intended as a one-off story, but positive response led to bringing him back almost a year later as a superhero.
Butt Monkey: Has become kind of a Running Gag both in and out of the comics, though it's technically not really deserved considering it stemmed from maybe two bad judgment calls on Pym's part at the most.
Catapult to Glory: Only capable of shrinking early in his career, Hank used a catapult to launch himself around town.
Domestic Abuse: Hank struck Janet during one of his mental breakdowns, leading to the end of their marriage. It's worth noting that he only struck her one time - which is still one too many - but it's become basically the leitmotif of his entire character.
And according to Jim Shooter, it wasn't even intended to be a deliberate hit. Apparently the writer had directed in the script that Hank accidentally backhand her while making a "I give the hell up, this is getting ridiculous" gesture, but that the artist, schooled in a style that demanded the most dramatic interpretation of a script, took that to mean hauling off and hitting her. There is also a conflicting rumor that the moment was meant as a Moral Event Horizon, in an Aborted Arc that would lead to Pym becoming an Avengers villain.
Also, it's remarked by several character that either Pym used to vent his frustrations by beating Janet almost daily, or every single individual in the Marvel Universe believes so.
During an heated argument with Wasp just before Avengers Disassembled She-Hulk refused to leave the room where they were arguing openly reasoning that Pym can't be trusted to be left alone with Janet while having a tantrum.
Later, when a seemingly drunk Tony Stark started to threaten the Latverian Ambassador and Pym tried to calm him, Tony bluntly sent him away, asking mockingly if "He hadn't a wife to beat".
During his tenure as a teacher in Avengers The Initiative, many of his students refused his autority, with Prodigy explicitly naming him a "Wifebeater" in public.
Furthermore even Jocasta, who's literally programmed to love him, had to agree that Henry Pym wasn't exactly a good husband for Janet.
In the Ultimate universe this scene is taken Up to Eleven as what starts off as an argument, turns into mutual combat, but quickly becomes a Curb-Stomp Battle when Janet shift into Wasp form.
Hank [Watching ants he called attack Janet]: "You shouldn't have called me small, Jan. You shouldn't have called me small."
Engineered Heroism: As Yellowjacket, Pym unleashed a giant robot called Salvation I that only he could stop in an attempt to appear heroic in front of his fellow Avengers.
Flight: Hank uses artifical wings to fly as part of his Yellowjacket and Wasp personas.
When Janet it found out what he was building this lead to the infamous panel. (Check Domestic Abuse)
Horse of a Different Color: Pym took to riding Korr, his flying ant companion, after Janet's flying power made the catapult superfluous.
Monster Protection Racket: At his lowest point, he built one of his lesser-known robots (Salvation-1) to stage a fight and make himself look good. He couldn't even manage that - Wasp defeated it and Hank was kicked out of the Avengers.
Never Live It Down: He provides the picture for the comics page, bitch-slapping his wife Janet/The Wasp. Sometimes he has trouble living this down in-universe as well.
Omni Disciplinary Scientist: While starting out as "merely" a brilliant biochemist, Hank's story arc eventually led to him becoming an innovator in numerous fields, including particle and quantum physics ("Pym Particles"), electronics/robotics/programming (Ultron) and of course, entomology. Eternity and told Hank he was Earth's "Scientist Supreme" because his prowess with wide-spread scientific disciplines allow him abilities akin to magic.
Tangled Family Tree: Legacy-wise he technically has 4 "grandchildren": Cassie Lang (by being Scott Lang's daughter and inspired by his heroism), Victor Mancha (built from Ultron Tech and human DNA) and both versions of the Vision (as the original was built by his "son" Ultron, and the second was a back-up copy of the original's programming). Mind you before their deaths in Avengers: The Children's Cursade Cassie and the second Vision dated, making them something of Kissing Cousins.
Also, if Ultron is his "son", Jocasta, his "robotic wife", can be considered both a robot clone of Janet and both Pym's niece, as Ultron created her, with some of Janet's memories, to satisfy his budding Oedipal Complex.
Jossed in-universe: Jocasta doesn't consider Henry Pym to be her grandfather, but, having created one of the first and the most powerful AI running rampant in the Marvel Universe, and being Ultron her creator, she staunchly and vocally believes that Henry Pym has to be regarded as the "God of Robots", and thus, when they dated, she claimed that her experience was more akin "Kissing God".
10-Minute Retirement: Pym has retired several times over the years, sometimes taking Janet with him, but it never stuck.
Wedding Smashers: The Ringmaster and the Circus of Crime attack during Hank's wedding to Janet, prompting a return of Pym's Giant Man persona.
What The Hell, Hero: Pym has gotten this more than a few times, but probably the biggest came when Pym led the Mighty Avengers. It turned out a member of their team, the Scarlet Witch, had in fact been Loki in disguise as part of one of his trademark evil schemes. Pym's response was to ask the God of Evil to join the Avengers for real. Every person in the room, including Loki himself, reacted this way, and his Avengers team actually broke up for a time on the grounds that Pym was either too crazy or too stupid to lead them.
Working with the Ex: Hank and Janet continued to work together as Avengers even when she started dating other men. It was awkward for both.
Ant-Man II (Scott Lang)
Adult Fear: He became a burglar first, Ant-Man later to properly care for his Ill Girl Cassie. He spent his life protecting and caring for her. Then Cassie followed in his footsteps becoming a teenaged heroine. She died, brutally killed in front of him. Scott was devastated.
Costume Copycat: Scott stole the Ant-Man suit from Hank Pym's house, using it to break into CTE to confront Darren Cross as "Ant-Man".
Ill Girl: Cassie Lang. At least when she was a child.
Papa Wolf: Go after Cassie and Scott will make you regret it.
Part Time Hero: Scott only donned the Ant-Man costume for brief periods early in his career, preferring to raise his daughter and, later, run his own electronics store.
Sympathetic Criminal: Scott turned to burglary as a last resort after his daughter is diagnosed with a congenital heart condition. His Earth's Mightiest Heroes incarnation provides the page image for Health Care Motivation.
The Atoner: The reason why he's in the Secret Avengers now. That, and Steve Rogers decided to give him a second chance.
Clear My Name: Subverted O'Grady did indeed steal the Ant-Man suit and evade SHIELD while on the run. But in order to get back into their good graces after he was found, he passes most of the blame for the serious stuff onto Mitch Carson (who was revealed to actually be a serial killer and about to brutally kill O'Grady anyway when SHIELD caught up to where Carson was holding him) and sold out Black Fox at the end of his series as well.
How Do I Shot Web?: Eric went through a trial-and-error stage after he stole the Ant-Man suit, burning Mitch Carson's face with his rocket boots and nearly killing an attempted rapist because he underestimated his own strength at insect size.
Jet Pack: The G.I. Ant-Man suit flies using a set of rocket boots. They can also be used as a weapon in the right circumstances.