Co-creator: Steve Ditko

Since his creation, Norman Osborn has easily been Spider-Man’s most lethal foe, but over the years, the man has evolved from a masked menace of the Wall Crawler into a business-suit-clad terror for the entire Marvel roster. Whether he’s fully decked-out in his Green Goblin garb, or ruling the nation with an iron fist as the director of H.A.M.M.E.R., Osborn’s mad grab for power is what puts him on this list.

And when Stan Lee and Steve Ditko first introduced him to readers in 1964, it was evident right away that he would be a major threat for years. As the character grew over the decades, Stan made his connection to Spider-Man more personal by introducing the world to Harry Osborn, Norman’s son and Pete’s best friend. It’s personal conflicts like this that differentiated Marvel from its competitors, and placed Osborn at the top of the villainous heap.