The Sinister Six were intended to appear as antagonists in Mark Webb's cancelled films The Amazing Spider-Man 3 and The Sinister Six.
At the end of 2014's The Amazing Spider-Man 2, the film teases the appearance of the Sinister Six. The Sinister Six was to include two characters that already appeared: the Green Goblin and the Rhino, and four new additions: Doctor Octopus, Kraven the Hunter, Vulture, and Mysterio. They would have first appeared in a supervillain-themed heist film called The Sinister Six, then taken on Spider-Man in The Amazing Spider-Man 3. Although teased at the end of The Amazing Spider-Man 2, the film's poor reception as well as Marvel/Disney making a deal with Sony to share Spider-Man in the Marvel Cinematic Universe led to the series cancellation.