Norman Osborn was experimenting with a formula that would make him superhumanly powerful when the chemicals exploded in his face. After this accident, Osborn spiraled into insanity. Attempting to achieve power beyond his wildest dreams, Norman planned to become the most powerful mob boss of all.

Remembering a giant green goblin monster from childhood nightmares, he created a costume that reflected that monster, and he became the Green Goblin. To prove his power and establish his reputation, he targeted the young superhero Spider-Man as his victim of choice, starting a never ending obsession with the wall-crawling superhero that would turn each other into their nemesis.