In Spider-Man 3 , Sandman is revealed to be the killer of Peter Parker 's uncle .
Following the events of Spider-Man 2 , as Peter Parker prepares his future with Mary Jane Watson , he bonds with an extraterrestrial symbiote , bringing out his anger , while facing Harry Osborn , seeking to avenge his father ’ s death , and an escaped thug who killed Peter 's uncle and becomes Sandman after a freak accident .
Spider-Man 3