The Rhino is a fictional character appearing in American comic books published by Marvel Comics. He was created by writer Stan Lee and artist John Romita Sr., and first appeared in The Amazing Spider-Man #41. The character is a Russian thug who underwent an experimental procedure that gave him an artificial skin covering and superhuman strength. Rebelling against the scientists responsible for his transformation, Rhino used his newfound powers to become a successful criminal, and soon clashed with superheroes like Spider-Man and the Hulk. The character is typically portrayed as a dimwitted brute, capable of great destruction, but ultimately easily deceived.

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. Led by Doctor Octopus, 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, Sandman, Electro, Mysterio, and Kraven the Hunter. While Doctor Octopus has generally remained its leader, the Sinister Six has had multiple variations of composition.