The Sandman (William Baker, a.k.a. Flint Marko) is a fictional character appearing in American comic books published by Marvel Comics. A shapeshifter endowed through an accident with the ability to turn himself into sand, he started out as a recurring adversary to the superhero Spider-Man, has been slowly redeemed over time, eventually becoming an antihero. The Sandman has also been an enemy of the Fantastic Four and is a founding member of the supervillain teams the Sinister Six and the Frightful Four.