The Sinister Six are a recurring villainous faction in Marvel Comics. They are a group of Spider-Man's enemies traditionally formed for the purpose of defeating their common foe. The two rules for every incarnation of the team, across all media, are that there must be six of them (no more, no less), and all six of them must be Spider-Man villains. The only incarnations of the team not to follow these two rules are the Sinister Twelve and the Sinister Seven.
After suffering three separate defeats from Spider-Man, Doctor Octopus, realizing that he would never beat his foe alone, decided to contact all of his enemies into order to assemble a team to finally overcome him. Only five villains, namely Electro, Sandman, Vulture, Mysterio, and Kraven the Hunter responded to Doctor Octopus' request, and together they formed the Sinister Six (a name Mysterio came up with, according to Spider-Man). However, realizing the group's conflicting personalities would not hold them together for long, Doctor Octopus formulated a plan to kill Spider-Man while each member retained their personal glory; that being to lure Spider-Man into six different carefully chosen locations where each member would have their chance to defeat the hero.
Later, the Six kidnap Daily Bugle secretary Betty Brant, figuring that she plays a larger role in Spider-Man's life, as well as another innocent bystander, Spider-Man's Aunt May. Vulture subsequently informs J. Jonah Jameson about the abductions, wanting him to inform Spider-Man, and, in turn, he informs Peter Parker, who had mysteriously lost his powers and was planning to become a normal teenager again. Regardless, Peter dons his Spider-Man costume and heads off to an electrical plant where he encounters Electro. During their fight, Spider-Man mysteriously regains his powers (speculating that it may have been a psychological block that caused him to lose his abilities) and beats Electro easily. Spider-Man then fought against Kraven and his two wild cats, Mysterio (who used robotic duplicates of the original X-Men), Sandman and Vulture, defeating them all one after another, before confronting Doctor Octopus and beating him too. Afterwards, all the villains were sent to prison.
Return of the Sinister Six
Many years later, Doctor Octopus decides to reassemble his old team, recruiting Electro, Mysterio, and Vulture after saving them from the law, blackmailing the reformed Sandman into joining him, and hiring the Hobgoblin to replace the deceased Kraven. After assembling the Six, Doctor Octopus tells them of his scheme to take the world hostage by planting a poison powerful enough to wipe out all life on Earth into Cordco Inc.'s satellite and threatening to release it unless the world's leaders give into his demands. He then sends Mysterio and Hobgoblin to steal a supply of burundite from Empire State University in order to make them immune to the poison, and Electro and Vulture to steal other supplies they will need.
The villains proceed to cause trouble across New York while preparing to enact Doctor Octopus' plan, and all successfully evade Spider-Man. With all he needs, Doctor Octopus prepares to create the formula to make him and his teammates immune to the poison, while informing them of the next phase of his plan: infiltrating the Cordco facility to insert the poison. Unaware to the other members of the team, however, Doctor Octopus is planning to betray them once they are no longer of use.
While in their New Jersey hideout, the Six train together while Octopus prepares the poison, not noticing Hobgoblin steal a vial of the poison while he is distracted. The Six soon attack the Cordco facility on Long Island to sabotage the launch, and end up battling with Spider-Man. He incapacitates Electro, Vulture and Hobgoblin before trying to stop Doctor Octopus from loading the poison into the satellite, only to have his webbing dissolved by Mysterio and fall into Sandman as a result. Doctor Octopus tries to kill Spider-Man, but Sandman refuses to let him do so, and so Octopus, prepared for his betrayal, uses a specially made gun to blast Sandman and turn him into glass. Doctor Octopus then orders the other Six members to kill Sandman, forcing Spider-Man to protect the inert villain while he loads the poison into the satellite.
During the fight, Hobgoblin sprays Spider-Man with the vial of poison he stole, only to find that the "poison" isn't killing Spider-Man at all. Doctor Octopus then returns and reveals the truth to his henchmen: he was never actually planning to hold the world hostage at all, as the chemical he loaded into the satellite is actually designed to make cocaine addicts convulse once they take the drug, and, since the only cure is the stolen burundite in his possession, the addicts will pay a fortune to continue their addictions, providing him with the funds to take over the world on his own. Furious at being betrayed, the Sinister Six turns on Doctor Octopus, but are all defeated by him and forced to escape as the police arrive, Spider-Man also left unable to capture any of them due to having to cure Sandman.
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.
Spider-Man: Turn Off the Dark
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.
Iron Spider's Sinister Six
After getting a recolored version of the Iron Spider Armour, Aaron Davis formed a new Sinister Six, which included the new Electro, the new original Hobgoblin, Bombshell, Spot, and Sandman.
Spider-Man: The Animated Series
The Sinister Six are called the Insidious Six in the 1994 animated series as Fox Kids' censors felt that the word "sinister" sounded too menacing for a children's program (even though X-Men, another Fox Kids children's program, had Mister Sinister as a villain). Formed in the beginning of season two's two-part premiere episode, the Insidious Six is created by the Kingpin to settle up his debt with his enemy, Silvermane, and consists of Doctor Octopus, Mysterio, Shocker, Chameleon, Rhino, and Scorpion. When they realize the connection of Peter Parker photographing Spider-Man, Doctor Octopus and Chameleon trick Aunt May into thinking Peter is ill and keep her imprisoned in a fake hospital. The Insidious Six overpower, tie up, and unmask Spider-Man (due to him temporarily losing his powers), only to assume Peter came to fight them himself because he could not find the real Spider-Man. Spider-Man, when his powers return, defeats them. During the gap between their appearances, Mysterio commits suicide by staying in an exploding building with the woman he loved. The Insidious Six return in "Six Forgotten Warriors", with Kingpin replacing Mysterio with Vulture. While they attempt to unlock a Doomsday machine, Chameleon betrays the group to side with his foster father. They are again defeated and incarcerated.
The Sinister Six appeared in The Spectacular Spider-Man, in the episode "Group Therapy". The group consists of Doctor Octopus, Sandman, Shocker, Vulture, Rhino, and Electro. As in the team's original version, Doctor Octopus is the leader. The villains pool their resources and organize a jailbreak orchestrated by Doc Ock himself, then go after Spider-Man. He eventually defeats them using his black symbiote suit. The team never actually uses the 'Sinister Six' codename amongst themselves; it is only used in the Bugle headline reporting their defeat and capture. In the episode "Reinforcement", Doctor Octopus arranges there formation of the Sinister Six (explicitly named as such this time) with an android stand-in for Mysterio and an illusion of the Vulture as Rhino and Sandman escape. Kraven the Hunter busts out Electro from Ravencroft, but Doctor Octopus is unwilling to join them. Spider-Man defeats the group when they attack the skating rink near the town's Christmas tree. Vulture remains Doctor Octopus' right-hand man until both their captures during the Valentine's Day summit.
The Sinister Six also appear in the Ultimate Spider-Man animated series. In the episode "Sinister Six", the first group consists of Doctor Octopus, Electro, Kraven the Hunter, Rhino, and Beetle coming together in Doctor Octopus' underwater lab in the Hudson River. For the group's sixth member, Lizard has a control device implanted on. The Sinister Six then attack Spider-Man. Lizard attacks Kraven as Spider-Man tricks Rhino into flooding Doctor Octopus' lab. Spider-Man retreats to the Statue of Liberty as the Sinister Six follows. The S.H.I.E.L.D. Trainees (Power Man, Iron Fist, White Tiger, and Nova) arrives to help fight the Sinister Six. Lizard escapes into the sewers as the rest of the Sinister Six are arrested. In the episode "Return of the Sinister Six", Doctor Octopus uses stolen OsCorp tech to invade Ryker's Island to equip Lizard, Electro, Rhino, Kraven, and Scorpion with armor. The armored Sinister Six give Spider-Man a hard time until Iron Patriot and the S.H.I.E.L.D. Trainees arrives. When the armored Sinister Six combine their attacks to take down Iron Patriot, Doctor Octopus injects Iron Patriot with the Goblin serum while Spider-Man restores Lizard back to Connors. Though Spider-Man wins against the Sinister Six, the Green Goblin gets away with Spider-Man's team. In the episode "New Warriors", Green Goblin leads several members of the Sinister Six (Doc Ock, Beetle, and Scorpion) during an attempted prison break on-board the S.H.I.E.L.D. Tri-Carrier during a showdown between Taskmaster's team and the New Warriors. The three Sinister Six members were eventually defeated by the amateur New Warriors. The Sinister Six return in the fourth season, Ultimate Spider-Man vs The Sinister 6 as Doc Ock formed the Sinister Seven, which consists of himself, Ultimate Goblin, Kraven the Hunter, Rhino, Hydro-Man, Electro, and Scarlet Spider, and the group appeared in "The New Sinister Six". They made their final role in the two-part series finale "Graduation Day," as the Superior Sinister Six consisting of Doctor Octopus, Kraven the Hunter, Scorpion, Rhino, Vulture, and Crossbones as the Lizard.
The Sinister Six appeared as the main antagonistic faction of Marvel's Spider-Man, The Sinister Six consists of Doctor Octopus, Mister Negative, Electro, Vulture, Rhino and Scorpion. To execute his plan to destroy Norman Osborn, Doctor Octopus used his mechanical arms to raid a Sable truck to steal Devil's Breath and broke the rest of the six out of the Raft. He sent his flunkies to attack major Oscorp locations in exchange for Otto fixing a problem the other members have. Spider-Man defeated Vulture and Electro near an Oscorp factory as well as Scorpion and Rhino near the docks. Mister Negative was denied his revenge against Osborn and his powers were disabled. Doctor Octopus was stripped of his arms and all of the six were sent to the Raft.
At the end of The Amazing Spider-Man 2Harry Osborn and Gustav Fiers plan to set up a crew, and Harry requests that they should keep it small. Fiers then arrives at Oscorp and retrieves the Rhino mech suit, giving it to Aleksei Sytsevich who is broken out of prison. At Oscorp Vulture's wings can be seen, along with Doctor Octopus's mechanical arms.
A spin-off The Sinister Six was planned to be released in 2016. Kraven the Hunter and Mysterio were confirmed to be members. Going by the ending of The Amazing Spider-Man 2 the crew will also have Doctor Octopus and Vulture. However the plans were cancelled due to unsatistying ratings of the The Amazing Spider-Man 2.