William Baker, otherwise known as Flint Marko, was a petty crook working for a local New York crime lord, Hammerhead, who never was able to get at his "big score" due to his constant arrests by the police. He was eventually bailed out of jail by several higher-ups at Oscorp Industries to serve as a guinea pig in an underground experiment meant to give him sub-dermal silicon armor, most likely as an attempt to recreate the Super-Soldier Serum by other means of genetic manipulation. However, the experiment went awry, and a combination of radioactive energy and the sand being bombarded into his body changed his molecular composition into sand, transforming him into the super-criminal, Sandman. He has since gone on to be a member of the Sinister Six, the primary superhuman team funded by Oscorp Industries to counteract both S.H.I.E.L.D.'s Avengers initiative and Spiderman.