Simpson is an only child but always had a hankering for masks to cover his face with. When the day came for him to leave Earth and join The Crew on the Skeld ship, he permanently adopted his identity and began making weapons out of bones. He would eventually partake in the Gravel Wars as the Fourth Generation Mercenary Pyro, not revealing his face but having an obsession of sorts. Dr. Toxic, Firecracker, Dr. Snowball, Neil, Scotch, Hot Head, Air Head, Emerald, and Birdie would eventually follow suit as the remaining 8 Mercenaries.