The Death of Green Goblin
One of Spider-Man's greatest tragedies began when his best friend, Harry Osborn, assumed the villainous identity of the Green Goblin. Blaming Spider-Man for the death of his father and knowing the hero's secret identity of Peter Parker, Osborn waged a personal war on Spider-Man for months, even tormenting his loved ones. In a climactic battle with Spider-Man, the Goblin's experimental strength-enhancing formula took his life.