Sinister Six

The Sinister Six was a group of Spider-Man's enemies that joined together to defeat their common foe. The original Six was formed and lead by Doctor Octopus, and also consisted of Electro, Sandman, Vulture, Mysterio, and Kraven the Hunter.

Later, after Kraven's death, Hobgoblin joined the group. The team has been added to a few times, and has been known as the Sinister Seven or the Sinister Twelve, depending on how many members.

One version of the Sinister Six was lead by Sandman, and another by Venom. The latter one was disbanded after Venom turned on his teammates, injuring Electro and Kraven and nearly killing Sandman, but Spider-Man stopped him by activating Venom's weakness: sound vibrations.

The Sinister Seven was formed by Mysterio to defend against Kaine, Peter Parker's homicidal clone, who was killing several of Spider-Man's foes. This group consisted of Mysterio, Electro, Vulture, Shocker, Beetle, Hobgoblin, and Scorpia.

Norman Osborn created the Sinister Twelve after the Scorpion busted him out of prison. Osborn, taking on his identity as the Green Goblin, brought together a large abundance of Spidey's foes to join his team, including Electro, Sandman, Shocker, Lizard, Vulture, Hydro-Man, Boomerang, Chameleon, Hammerhead, and Tombstone. Mac Gargan (the Scorpion) later arrived as the new Venom, having gained the Symbiote in between that time. The Twelve ganged up on Spider-Man and his ally Black Cat, and almost killed them both, until Captain America, the Fantastic Four, and some other heroes arrived and helped defeat them.

During the aftermath of the Marvel Civil War, Doc Ock gathered a short-lived Sinister Six with himself, Vulture, Shocker, the Lizard, Trapster, and the Grim Reaper.

The current version of the Six is made up of Doc Ock, Mysterio, Electro, Sandman, Rhino, and Chameleon.

The group appeared in Spider-Man: The Animated Series, but were called the Insidious Six (because censorship wouldn't allow them to use the word "Sinister"). It was founded by the Kingpin and it's members were Doc Ock, Mysterio, Rhino, Chameleon, Scorpion, and Shocker. The Vulture joined later after Mysterio's death.

The Sinister Six were also featured in The Spectacular Spider-Man and were made up of Doc Ock, Electro, Sandman, Vulture, Rhino, and Shocker. The second version of the Six included Mysterio and Kraven to replace Doc Ock and Shocker.

In Spider-Man: Turn Off the Dark, the Sinister Six is created by the Green Goblin for the purpose of destroying Spider-Man. Here, it consists of Electro, Carnage, Swarm, Kraven the Hunter, Lizard, and original character Swiss Miss. In this version, their comic-book origins are ignored. Instead, they share a common origin as former research scientists whom Green Goblin deliberately mutates into "freaks," in part as punishment for having abandoned Osborn Industries.

Origin
After suffering three defeats at the hands of Spider-Man, Doctor Octopus realized that he needed help against the web-slinger. He got in touch with every super-powered villain who had battled the wall-crawler. In the end, five other super-criminals heeded Ock's call---the Vulture, Electro, Kraven the Hunter, Mysterio, and the Sandman. However, Doctor Octopus recognized that he would never be able to control these super-villains. They were incapable of working together or functioning as a well-oiled machine. Instead of trying to change this unruly bunch, Doctor Octopus conceived a battle plan that exploited their individual appetites for personal glory. Each member of the Sinister Six would stage a separate battle with Spider-Man at a carefully chosen location. One by one the criminals would fight him until the wall-crawler was finally destroyed.

Members

 * Doctor Octopus
 * Electro
 * Sandman
 * Vulture
 * Mysterio
 * Kraven the Hunter

Later Members

 * Hobgoblin
 * Gog
 * Venom
 * The son of Kraven
 * Shocker (Sinister Seven)
 * Beetle (Sinister Seven)
 * Scorpia (Sinister Seven)
 * Lizard (Sinister Twelve)
 * Green Goblin (Sinister Twelve)
 * Hydro-Man (Sinister Twelve)
 * Hammerhead (Sinister Twelve)
 * Tombstone (Sinister Twelve)
 * Boomerang (Sinister Twelve)
 * Chameleon (Sinister Twelve)
 * Trapster
 * Grim Reaper
 * Chameleon
 * Rhino