This isn't how I imagined I'd die, looking at my son and seeing a stranger.
~ Norman Osborn talking to Harry.
Norman Osborn is the overarching antagonist of Marc Webb's The Amazing Spider-Man franchise. He is the unseen overarching antagonist in The Amazing Spider-Man, a minor, yet pivotal antagonist in The Amazing Spider-Man 2 and was planned to return as the main antagonist of The Amazing Spider-Man 3 as the King Goblin before its cancelation. He is the founder and CEO of Oscorp Industries and father of Harry Osborn.
Barely anything is known about Norman Osborn's early life, except for that he founded the Osborn Corporation, which he and everyone else nicknamed Oscorb, and became wealthy out of the company's success. When his son, Harry, was young, he sent him into the boarding school, causing their relationship to falter.
In The Amazing Spider-Man, Norman Osborn's existence is revealed via intercharacter dialogue and the presence of Oscorp Industries. Early in the film, he is shown as a vague silhouette on a monitor in the Oscorp lobby, referencing him as the company's founder.
Humorously, his silhouette is shown holding an orange globe of the company's logo, a subtle reference to his goblin bombs. It is mentioned that he has been afflicted by an illness, which is the catalyst for Dr. Curt Connors' development of the regenerative serum.
Osborn is never seen in person, however, but is mentioned several times. In the film, Dr. Rajit Ratha had pressured Dr. Connors to develop an antidote that would cure Osborn of a rare but deadly disease. Connors, thinking that there is too much risk, refuses to do so, and Ratha fires him as a result.
Not very much is known about Norman, other than that he had a debilitating disease called 'Retroviral Hypodysplasia' which eventually killed him. It is also mentioned that the is the founder of Oscorp. Dr. Connors' and Dr. Ratha's experiments with lizard DNA were an unsuccessful attempts to cure him, until Connors used the serum on himself, transforming into the monstrous Lizard as a result. After the Lizard was defeated (for the first time), Connors and Ratha permanently quit their works, and Connors was locked in a mental institute.
In The Amazing Spider-Man 2 Norman's estranged son, Harry, returns after many years away in boarding school and visits him in the hospital, whereby this point Norman is in extremely poor health and barely alive. Because of his disease, Norman has greenish, scaly skin and his fingernails turned into claws. Norman explains to Harry that his illness is genetic and that Harry is at the right age where it usually begins to show. Before his death, Norman gives Harry a mysterious device, saying that it contains his life's work. The next day, it is reported that Norman succumbed to his illness.
Later it is revealed that Norman Osborn worked along with Peter Parker's father, Richard. When Richard tried to destroy his work and escape with his wife, Mary, Norman sent his man after them to kill them both, which resulted in Richard and Mary perishing in a plane crash.
Norman was a very ambitious, intelligent, brilliant and bright person, but he was also very greedy, corrupt and selfish. Even though he often acted nice and calm towards others, he was actually cunning, deceitful and immoral since he was willing to weaponize Richard's research (unbeknownst to the latter) for foreign countries, thus he was eager to betray his own country for profits.
He was also ruthless, grudging and vengeful since he wanted to kill both Richard and Mary after finding out that Richard wants to destroy his work and even willingly faked evidence against Richard in order to discredit him. It is also implied that he mistreated Donald Menken in the past, suggesting that he was also abusive. Despite his evilness, he truly loved and genuinely cared about his son, Harry, and, despite sending him to the boarding school, he gave him a device that was containing his work, hoping that it would save his son from death.
For unknown reasons, Chris Cooper was never credited for his appearance as Norman in The Amazing Spider-Man 2.
There was a post-credits scene in The Amazing Spider-Man 2 but it was deleted from the final cut. The scene shows Gustav Fiers walking through the Special Projects and going to Door 3. There, you can see Norman's frozen head. Gustav says "Wake up my friend" and Norman suddenly opens his eyes. Also, when Norman passes away, the nurses are seen rushing in to cover up his body. One of the nurses is pushing a rack with a jar on it. That could be the jar where Norman's frozen head was placed.
Osborn, in other Spider-Man media, takes on the identity of the Green Goblin, a famous Spider-Man villain. However, in this universe, it is his son Harry who first takes on the identity of the Green Goblin since Norman dies before having a chance of doing so.
It was rumored that Norman would come back as the Ultimate incarnation of the Green Goblin. However, since all future The Amazing Spider-Man films were canceled, this never happened.
Even though Norman doesn't become a Green Goblin in this universe, he is still a villain since he is a greedy and corrupt businessman who was willing to betray his country for his own benefits, sent his man to kill two people, and even wanted to discredit Richard Parker (and succeeded in doing so).
Also, because his body was deteriorated by his disease, Norman has a goblin-like appearance.
This is the first version of Norman Osborn that never interacts with Spider-Man.
Chris Cooper had stated that Norman's appearance in The Amazing Spider-Man 2 would be the introduction to the character, and a return in The Amazing Spider-Man 3 would be on the cards.
Marc Webb confirmed that Norman would appear in The Sinister Six film. However, as the Spider-Man franchise was rebooted in order to be part of the Marvel Cinematic Universe, this version of Norman Osborn is not a part of that continuity.