Hank Pym is a fictional character in the Marvel Comics universe, created by writer Stan Lee and artist Jack Kirby. He first appeared in Tales to Astonish #27 in 1962. Pym is a brilliant scientist known for his work in biochemistry and quantum physics. He is best known for developing the Pym Particles, which allow him to shrink in size and communicate with insects. Hank Pym has taken on several superhero identities, including Ant-Man, Giant-Man, and Yellowjacket. He is also a founding member of the Avengers, a team of superheroes that includes characters like Iron Man and Thor. Pym's complex personality and struggles with his identity have made him a compelling character in the Marvel narrative.