The man known only as Flex Mentallo was originally the only superhero of a small town in Ohio. Flex gained his powers through unrevealed circumstances, although rumor has it that he was a man named Mac. Tired of having sand kicked in his face, Mac wrote away in response to a "Make you a man" ad and received a book on the power of Muscle Mystery. Flex learned how to flex his muscles to do almost anything, and became the Hero of the Beach. Or so the rumors say.
Flex was abducted by the Bureau of Normalcy and put to work for the U.S. government. He broke free but his long years of imprisonment had made him forget who he was. With the help of the Doom Patrol, he eventually regained his memories and traveled with the group to Danny the Street to help them find Niles Caulder.
