Hank Pym

Created within American comic books, Dr. Henry 'Hank' Pym debuted in Tales to Astonish #27 (January 1962). In his original comic-book origin he is a biochemist who discovers a set of subatomic particles he dubs 'Pym particles,' entraps them in two separate serums, and tests them on himself; reduced to insect size, he becomes trapped in an anthill before escaping and using a reversal formula to return to normal size. Over time the character was revived and reinterpreted across Marvel titles and media but retains this core scientific-origin premise.

There is no single fixed visual description outside of media-dependent portrayals. In comics Pym is presented as a human scientist who adopts multiple costumed guises linked to size-change: Ant-Man (insect-themed small-sized suit), Giant-Man/Goliath (enlarged form with corresponding costume), Yellowjacket (distinct identity and costume), and briefly the Wasp identity after Janet van Dyne's death. In film the character is portrayed as an older scientist figure, played by actor Michael Douglas in MCU films.

Pym is characterized primarily as a scientist-inventor: he discovered and named 'Pym particles' and formulated serums that enable shrinking to insect scale and growth to gigantified scale, enabling his various costumed identities. He is an inventor of advanced technologies, most notably the creation of the robotic villain Ultron. Narratively he alternates between heroic action (team founder/member of the Avengers) and scientific work, and his history includes episodes of mental and emotional strain tied to identity shifts and the consequences of his inventions.