What about the Chameleon?
He'd make a great villain, provided he has the more realistic, CIA/NSA level "master of disguise" ability of assuming identities as opposed to a Mystique-like capability to shapeshift altogether.
It'd make for a potential plot too. Seeing as how Harry knows Peter and Spider-Man are one in the same, he hires the Chameleon to assume Parker's identity and smear his character by framing him for a crime, most likely an assassination attempt
(seeing as how the Chameleon was also a hitman for hire), forcing Parker into hiding and remaining in his Spider-Man alter-ego to carry out the means to clear himself. Harry may also either
(depending on which way the writer would want to go) hire a mercenary to don the "goblin" suit to be the Hobgoblin, or he may choose to be the Hobgoblin himself to torment Spider-Man in his obsession to avenge his father. It's the perfect two-pronged attack against Spider-Man, as he'll be so tied up with the Hobgoblin that he'll have a difficult time trying to clear himself from the Chameleon's identity-assumed activities.
It's a hypothetical plotline, but it's a far more produceable one than the Venom/Carnage stories. Besides, Venom is a mentally unstable and incredibly violent anti-hero, while Carnage is a serial killer possesed by a cast-off of Venom's symbiote, which was already disturbed as it is. Even if the producers were to consider these characters for filming, there'd need to be a level of wanton destruction, murder, and anarchy on par with the early 90's
Maximum Carnage story arc to do any justice to these characters, and such intense violence often comes at the price of an
R rating, which would kill the franchise, since it banks so heavily on the young audience.
Note: Yes, I have given this a lot of thought, as I myself am a hardcore Spider-man fanboy and have been ever since I dressed up as him for my first Halloween at 5 years old.
