Scott Lang lost his job as an electronics expert, and briefly turned to crime. After being released from prison, his daughter's life was threatened, so he 'borrowed' Henry Pym's Ant-Man costume. As Ant-Man, Lang joined the Avengers, ultimately perishing in the Avengers Disassembled crisis.
This is an old custom of mine, completed long before the ToyBiz figure. The body is movie Daredevil's, with a He-Man head inside a Professor X helmet. The helmet is not removable, though the faceplate is. Costume details were created from rubber bungee, elastics, and craft store beads. Photos by Nara and myself. Thanks for looking, feel free to comment, and Make Mine Marvel!