Spider-Man 3 features a fictional character.
Harold `` Harry '' Osborn is a fictional superhero and ex anti-hero in the . Sandman ( William Baker a.k.a. Flint Marko ) is a fictional supervillain appearing in American comic books published by Marvel Comics . Spider-Man 3 . Harry Osborn still seeks vengeance for his father 's death , and an escaped Flint Marko falls into a particle accelerator and is transformed into a shape-shifting sand manipulator . During pre-production , Raimi originally wanted another villain to be included along with Sandman , but at the request of producer Avi Arad he added Venom , and the producers also requested the addition of Gwen Stacy .