The Sinister Six are a group of supervillains appearing in American comic books published by Marvel Comics, mainly those featuring Spider-Man. The members are drawn from the character's list of enemies, with the original members forming the team in The Amazing Spider-Man Annual #1 (October 1964). Led by Doctor Octopus (introduced in issue number 3), the team in its premiere followed swiftly the very early appearances of many of the most enduring members of Spider-Man's rogue's gallery: Vulture (the title's first super-villain, in issue #2), Sandman (issue #4), Electro (#9), Mysterio (from #13), and Kraven the Hunter (#15). While Doctor Octopus has generally remained its leader, the Sinister Six has had multiple variations of composition. The team has been adapted into various forms of media, mainly in animated series and video games. A film based on the team is in development as part of Sony's Spider-Man Universe.