Fan Casting Dr. Bill Foster in Edgar Wright's Astonishing Ant-Man

A former Golden Gloves boxer, Bill Foster was partnered with Dr. Hank Pym at the Dynatechnics lab where they worked. The two did not always get along, but they respected each other enough to keep their disagreements civil. When Pym discovered particles that interacted with a sidereal dimension where mass was virtual instead of real, the only one he confided in was Foster. When the diminutive adventurer Ant-Man appeared on the scene, Foster confronted Pym about it at work the next day. Foster agreed to keep Pym's identity as Ant-Man a secret, but only if he was permitted to help research other uses for the Pym particles, as he dubbed them. Foster later developed a chemical solution which contained Pym particles that would increase an object's size and mass beyond its default size. However, Pym initially seemed uninterested in this aspect of the particles' properties, and Foster himself wondered how it could be utilized. And then the lab was raided by the corporate spy called Doctor Nemesis, who in the process stole Foster's notes on the Pym particles. Designing a superhero uniform for himself, Foster injected himself with the chemical solution, granting him the power to change his height at will. Foster made his debut as Giant-Man during a fight Ant-Man and his partner Wasp against Doctor Nemesis, turning the tide by giving Nemesis someone who could fight back at larger size. Since then, Foster has only rarely donned his Giant-Man identity, though he stands ready to assist Ant-Man, Wasp, and other heroes when needed.