Harry discovers that his father developed an advanced version of the Goblin Formula, but was unable to test it before his final battle with Spider-Man. After testing it, he ingests the new formula. When he spies Spider-Man investigating his townhouse, Harry loses his temper and attacks him as the Green Goblin.
Harry takes on the Green Goblin persona and technology after his father's death, which he blames on Spider-Man and in turn Peter, and is influenced by hallucinations of his father to kill Peter, but sacrifices himself to save Peter, Mary Jane, and his son.
Harry Osborn is the CEO of Oscorp Industries, and the son of the company's founder, Norman Osborn. Due to a recessive gene called 'Retroviral Hypodysplasia' passed on from his father, Harry quickly began to succumb to a disease that turned some of his skin green and deformed.
Harry had inherited his mother's Oshtoran Syndrome and began to experience complications. Unwilling to put his friends through the hardship he felt during his mother's illness, Harry kept his condition a secret, pretending to be busy or hungover from partying when his sickness got in the way.
In the Spider-Man (2002) game, Harry Goblin is playable as the Green Goblin (Norman Goblin's original suit), making him the only Goblin to become both Goblins but the game isn't canon since Harry didn't discover his father was the Green Goblin until the end of the second movie.
The Amazing Spider-Man 2 (2014) - Becoming Goblin Scene (5/10) | Movieclips
Why did goblin betray Harry?
However, despite being rescued by them, Griphook's general mistrust of wizardkind resulted in him betraying Harry Potter, Ron Weasley, and Hermione Granger. He betrayed them because he believed they would not hand him the Sword of Gryffindor, after destroying the Cup and other Horcruxes.
He uses advanced Oscorp armor and equipment to terrorize New York City and battle Spider-Man, but ultimately dies when he is impaled by his own glider. A hallucination of Osborn haunts his son Harry in Spider-Man 2 (2004) and Spider-Man 3 (2007).
Norman Osborn's experiments increase his strength but lead to a mental breakdown, as he becomes a cackling, evil presence often driven by a very personal vendetta with Spider-Man.
Knowing that Peter had taken photos of the hero, Harry asked him to get in touch with Spider-Man. Later, Spider-Man appeared in Harry's home but refused to give him his blood regardless of what Harry offered him, as he believed his blood would have a negative effect on Harry if it wasn't compatible.
Because of the symbiote's influence on his personality, Peter refused to return the symbiote to Harry, even to save his best friend's life. Incensed, Harry extracted the symbiote from Peter and rebonds with it, transforming into Venom and wreaking havoc across New York City as Peter and Miles scrambled to stop him.
When he regained all his memories, Harry submerged himself in a new version of the formula that his father had been working on before disappearing, making himself stronger than Norman believed possible. It was enough for Harry to match Spider-Man blow for blow.
In a desperate bid to take a greater degree of control over his company, Oscorp, Norman develops a serum to enhance human strength and intelligence, which does indeed succeed on those parameters, but also causes him to descend into violent insanity.
In the end, the Goblin could easily overpower the hero and pummel him with punches that could last longer than most, as he's never been shown to get tired from a long fight. While it's likely he could be beaten into submission, it's a war of attrition that Cap simply can't overcome.
Ben was killed when a burglar was robbing their house. Ben accidentally surprised him causing the burglar to shoot him. His death sparked the transformation of Peter Parker into Spider-Man. He once returned for five minutes as part of a birthday present from Doctor Strange for Peter Parker.
Meanwhile, Harry finds love with Liz Allan and marries her, and they have a son Normie, named after his father. Though his descent into madness after taking the Goblin formula lands him in a superhuman prison. Liz couldn't testify against Harry so he was released from captivity.
Harry Osborn, an old friend of Peter and MJ's, develops Oshtoran Syndrome and undergoes an experimental Symbiote treatment. Harry discovers Peter's secret identity as Spider-Man, and Peter discovers Harry's Symbiote powers.
The villans are very poorly constructed, specially Harry Osborn, that was so well constructed at the previous trilogy. It's was kinda desappointing. Electro's motivation was also weak, maybe the movie tries to introduce to many characters at once.
The Norman version of the Green Goblin is usually regarded as Spider-Man's archenemy. The second Goblin, Harry Osborn, is Norman's son and Peter Parker's best friend. He has the same powers as his father.
When Otto attempts to kill them both, Harry sacrifices himself to save Peter. As he dies in Peter's arms, he apologizes for being weak with Otto and his father, though Peter reassures him that he was not.
The Goblin formula had an unfortunate side effect of making Osborn insane; defects in his personality were strongly augmented by the serum, resulting in dangerous mood-swings and hallucinations.
However, Green Goblin found himself alive and transported through the Multiverse due to Doctor Strange's failed spell. Lost in an unfamiliar reality, Osborn retook control of his mind, seeking refuge from Spider-Man, who sought to cure Osborn. However, Green Goblin retook control and murdered May Parker.
After saving his Aunt, Spider-Man and the Goblin had an epic battle across New York City that culminated with the villain unmasking Peter in front of his colleagues before killing him with a pumpkin bomb in Spectacular Spider-Man #263 (by Howard Mackie and Luke Ross).
How did Green Goblin find out Spider-Man's identity?
It happens at 1:31 : Then later on when they (Peter and Norman), were having dinner at Aunt May's house. Peter said that a bike messenger knocked him down (to explain how he got the cut) at 2:48, but Norman (Green Goblin), recognized it from when he sliced him (Spider-Man), in the burning building with the baby in it.
