There are few villains in the Spider-Man universe who have had as much of an impact as has Norman Osborn, AKA the "Green Goblin." From the beginning, Norman has been Peter Parker's most challenging nemesis. Brilliant, insane, absurdly wealthy and possessing knowledge of Spider-Man's true identity, Osborn is one of Peter's most powerful foes, and one who keeps coming back despite numerous death scenes and imprisonments.
Before Norman became the Green Goblin, he was just another evil corporate scumbag in a three-piece suit and tie. Osborn's company--Osborn Industries--specialized in the development of chemical enhancements, as well as robotics and weapons development. Norman became the Green Goblin when, after seizing control of Osborn Industries from his partner Professor Mendel Strohmm, he attempted to inject himself with a new super-strength serum Strohmm had developed. The unstable chemicals exploded, leaving Norman hospitalized but with super strength and an increase in genius. He also developed a case of the galloping crazies, which only helped push him away from the role of "Ruthless Industrialist" and into the role of "Ruthless Supervillain."
Weapons and Powers
Marvel really pulled out all the stops when it came to the Green Goblin's powers. Norman is essentially a toned-down cross between Wolverine and The Hulk, with just a pinch of Reed Richards thrown in for good measure. In addition to his incredible strength--lifting up to 9 tons under optimal conditions--and smarter-than-MENSA brain power, "Gobby" can also regenerate dead or diseased tissue and organs. His personal weapons are pumpkin grenades--which are exactly what they sound like--gauntlets capable of shooting out 10,000 volts of electrical current, and a specialized gas that nullifies Spider-Man's spider sense.
Norman Osborn is one of the few original Marvel supervillains who isn't just some lone random psychopath. Osborn has one surviving family member; his son Harry, who also just happened to be Peter Parker's best friend during the Golden Age of comics. He also had a wife at one point, but she died a year after Harry Osborn's birth, which in turn left Norman bitter and cynical about life in general.
Claims to Fame
Osborn's dastardly schemes and evil deeds are far too many to list in one place, but even amid all that evil, one particular instance stands out. Gobby forever left his mark on Marvel comics--and in Spider-Man's life in particular--by being the first supervillain to successfully kill off a superhero's love interest. Gwen Stacy, daughter of the local police captain, was Peter's girlfriend in early issues of the comic. Osborn kidnapped her and threw her off a bridge to taunt Spider-Man. Spider-Man caught her with his webbing, but the resulting inertia snapped her neck like a twig, resulting in one of the few permanent deaths ever seen in Marvel Comics. This forever cemented Norman Osborn as Peter Parker's greatest nemesis, and one of the series' greatest villains. He is also one of the only villains to discover Spider-Man's true identity.