In the Spider-Man film series, Harry, played by James Franco, is Peter Parker's closest friend. He constantly tries to appeal to his father, who is very invested in his work, and he is jealous of Peter's intelligence. He dates Mary Jane Watson during the first film, though she eventually falls for Peter, and he manages to somewhat reconcile his feelings with his father. After his father's death as the Green Goblin, Harry believes that his father was murdered by Spider-Man and seeks revenge.
Harry takes over Oscorp in Spider-Man 2, forming an alliance with Doctor Octopus to get his revenge. Though it fails, he learns that Peter is Spider-Man. Afterwards, he begins to hallucinate, seeing his father's image in a mirror, demanding that Harry avenge him. He smashes the mirror, and finds a hidden room with the Green Goblin equipment and serum behind it, realizing that his father was the infamous Green Goblin.
Becoming the New Goblin in Spider-Man 3, he attempts to take revenge, which eventually leads to a symbiote-possessed Spider-Man throwing a pumpkin bomb at him, which scars the right side of his face. As the New Goblin, Harry is the primary antagonist for the first half of the film. However, after learning the truth of his father's death from his butler Bernard, he helps Spider-Man save Mary Jane from Venom and Sandman, although he is mortally wounded by Venom in the ensuing fight after sacrificing himself to save Peter. He dies with Peter and Mary Jane at his side, just after he and Peter reconcile their friendship with each other at last. Peter and Mary-Jane attend Harry's funeral together, with their hearts broken.