Sandman (William Baker a.k.a. Flint Marko) is a fictional supervillain appearing in American comic books published by Marvel Comics. A shapeshifter endowed through an accident with the ability to turn himself into sand, he began as a villain and later became an ally of Spider-Man. The character has been adapted into various other media incarnations of Spider-Man, including animated cartoons and the 2007 film Spider-Man 3, in which he is portrayed by Thomas Haden Church.