When it comes to Spider-Man's cast of villains, it's hard to get more iconic than the Green Goblin. The villain is so intrinsically tied in with the web-slinging hero that it's only natural both of his first two live-action franchises sought to adapt their own versions of the Goblin.
Thus far, the MCU has strayed away from the emerald path, but it's inevitable that their eyes will turn Norman Osborn's way at some point. And when that day comes, the best story to look toward for inspiration of how to do the Green Goblin right won't be from the mainstream version of the character, it will be the Ultimate Green Goblin.
While the issue of Spider-Man's true arch-nemesis is usually a toss-up between Green Goblin, Doctor Octopus and Venom depending, it stands to reason that the MCU will end up doing their own take on all three sooner or later. The MCU has been careful with its iteration of the Spider-Man story to stray too close to its predecessors, looking to different Spidey villains to serve as antagonists to help differentiate the new direction. As they do eventually turn to more familiar villains, though, it will be central to their strategy to do each villain with a new take that won't seem familiar to the casual fan.
Both of the previous versions of the Green Goblin on film harkened back to their classic 616 comics counterpart. In the Sam Raimi-directed feature, Norman Osborn was a weapons manufacturer who tested an experimental super-soldier serum on himself and absconded with high tech weaponry that allowed him to menace the city. In subsequent films, his son, Harry, took up his mantle, adopting the same methods. For the Marc Webb-directed sequel The Amazing Spider-Man 2, the film actually started with Harry flinging bombs from the glider.
The Ultimate Green Goblin is a much more drastic departure for the character. Tied in inherently with Spider-Man's origins, Norman Osborn puts his full focus on the serum his company develops in trying to replicate the success of Captain America decades prior. When Norman discovered that one of their spider escapes and imbued Peter Parker with his fantastic spider-like powers, Norman tests the formula on himself. Rather than gaining generic super strength, he transforms into a goblin-like monster with horns who hurls explosive fireballs from his hands.
Not only does his powerset and appearance distinguish him significantly from the previous live-action versions of the character, but his role as a manipulator and his relationship to Peter stands out in a much greater depth of detail. While the Raimi Osborn had a surface-level connection between his origin and Peter's, Ultimate Osborn's entire character revolves around that connection. He obsesses over Peter to a psychotic degree, and the greater a hero Spider-Man becomes the more he twists that into being his own success since he takes responsibility for Peter's "creation."
What ends up working about Ultimate Green Goblin is how his obsession with Peter and his various schemes throughout the comics end up having lasting material impacts in Spider-Man's story. His very first attack on Peter's school served as Spider-Man's major debut as a superhero to the world, clued in the media to the idea that Spidey likely attends Midtown High, traumatized some of Peter's classmates like Liz Allen and was a frequent touchstone for conversations relating to the hero.
Subsequent schemes shaped the world just as impactfully. When Norman broke out of prison and formed the Sinister Six (with membership including Peter himself) to attack the White House, it proved that Spider-Man was fighting major threats capable of going toe-to-toe with the Ultimates rather than purse snatchers and muggers. When Norman tossed Mary Jane off a bridge in a scene reminiscent of Gwen Stacy's iconic death, Peter may have saved her but her subsequent PTSD affected her relationship with Peter thereafter.
Such lasting consequences are probably one of the best things an MCU incarnation of Ultimate Green Goblin could truly use to hit the ball out of the park. Raimi's Green Goblin also threw Mary Jane off a bridge, but the experience didn't really seem to stick with her in any way beyond making her a flat damsel in distress. Webb's Green Goblin did kill Gwen Stacy, but the closing minutes of the movie showed Peter growing past that experience after a brief montage of grief.
For the MCU Spider-Man, the villains thus far have been great, but they have not had the lasting impact or importance that the Ultimate Green Goblin could. While Vulture's sendoff had consequences for Peter's romantic interest Liz Allen and Mysterio revealing his secret identity at the end of Far From Home both classify as lasting consequences, neither villain stuck around to stew in the aftermath. What's more, neither had anything at all to do with the MCU Spider-Man's origins.
In fact, the origins of the latest live-action Spider-Man remain a mystery due to Marvel's efforts to stray away from rehashing the story. The audience doesn't even know what precisely happened to Uncle Ben, let alone how exactly the web-slinging hero got his powers. Introducing the Ultimate Green Goblin, with his roots tied firmly in with Spider-Man's, would be a great way to revisit and reexplore what those origins are now that the franchise has established itself as independent.
Ultimate Green Goblin would be a unique twist on a familiar classic, at once simultaneously bringing in an element to the story of Spider-Man that is vital and at the heart of the character while introducing it in such a way it did not feel rehashed, overly familiar, or redundant. The Ultimate Universe has potential that has gone untapped and unexplored, and the Green Goblin may just be the best place to start remedying that process.