The Sinister Six is a group of supervillains from the Marvel Comics universe, primarily known for their battles against Spider-Man. Formed by Doctor Octopus, the team typically includes other notable villains like Vulture, Mysterio, Kraven the Hunter, Electro, and Sandman. Their goal is to defeat Spider-Man and eliminate him as a threat. The Sinister Six first appeared in The Amazing Spider-Man Annual #1 in 1964. Over the years, the lineup has changed, with various villains joining and leaving the group. They are known for their strategic planning and teamwork, often working together to take down their common enemy, Spider-Man.