J. Jonah Jameson hires Dr. Farley Stillwell, a genius in genetic engineering, to make a new superhero that can match and defeat Spider-Man. With a willing participant, Mac Gargain, they engineer the DNA of a scorpion and him together to form a new hero, the Scorpion. However, when Gargain thinks they have turned him into a freak, the hero turns into a monster and goes on a rampage. Spider-Man is forced to step in to stop the creation from killing its creator.