In the Ultimate Marvel universe, the Defenders are a group of amateur vigilantes who dress up as superheroes. None of them have superpowers, although they claim to be experienced in crimefighting. Henry Pym is invited to join them, and he accepts, adopting a new identity, Ant-Man, to avoid the potential legal problems of using his growth serum, as it has become the official property of the government. Their members include Ultimate versions of Power Man, Hellcat, Nighthawk, Valkyrie, Black Knight, Son of Satan and Whiz-Kid. The Ultimate Defenders are much more interested in becoming celebrities rather than actually stopping crimes or saving lives.