Mad scientist archenemy of the superhero Spider-Man; originated in Amazing Spider-Man #3. Named because his powers consist of four robotic tentacle-like arms, which were welded to his body in a laboratory accident. Played by actor Alfred Molina in the second Spider-Man movie. A much better supervillain than Venom, in my opinion.
All superheroes have archenemies: Superman has Lex Luthor, Batman has the Joker, and Spider-Man has Doctor Octopus.