Scott Edward Harris Lang is a former professional criminal who, despite trying to go straight to raise his daughter, was convinced by Hank Pym to take on the mantle of the Ant-Man.
Real Name: Scott Edward Harris Lang
Portrayed by: Paul Rudd
He fought against Pym's former protégé, Darren Cross, who had gone insane while trying to recreate the Pym Particles, leading to Lang having to defend his friends, family and the world as the Ant-Man.
2. Captain America: Civil War
When all of the Avengers separated into two separate factions over the Sokovia Accords, he was recruited to Captain America's side by Falcon. Though given a chance to back out as the faction, as they would be working outside of the law, Lang scoffed at the warning; being a wanted man was hardly a new experience for him. Lang was subsequently arrested following the Clash of the Avengers before being freed from the Raft by Captain America.
He, along with Hawkeye, returned to a normal life by making a deal with Thaddeus Ross of the United Nations, which resulted in him being placed under house arrest.
3. Ant-Man and the Wasp
Two years after the Clash of the Avengers, Lang remained under house arrest, spending much of his time playing with his daughter and learning magic tricks. One day near the end of his sentence, Lang received a dream from Janet van Dyne in which he saw a younger Hope.
Lang notified Pym and Hope, who were on the run because of the Sokovia Accords. Hope, now having taken up the mantle of Wasp, broke Lang out of his home whilst successfully evading police detection, and took him to her father's portable lab.
At Pym's lab, the three learned that Lang was quantumly entangled with Janet, and that they had a limited amount of time to retrieve her from the Quantum Realm.
Ava Starr, and Bill Foster, a former colleague of Pym's, sought to steal the lab, and use Janet's energy to heal Ava of her intangibility and pain. Sonny Burch, a criminal businessman also sought out the lab for its advanced technology. Together Lang and Hope were able to fight them off while Pym went into the Quantum Realm himself, successfully saving his wife.
Upon her return, Janet was able to heal Ava. Lang finished his sentence, and was no longer under house arrest.
Not long after, Lang arrived in Luis's van on a roof with a portable Quantum Realm portal for Pym, Hope, and Janet to acquire a substance to help heal Ava. While in the Quantum Realm, Thanos succeeded in gaining all six Infinity Stones from the Avengers and the Guardians of the Galaxy, thus wiping out half of all life in the universe.
During a countdown before his return, Pym, Hope, and Janet all turned to dust, leaving Lang stranded in the Quantum Realm.