Doctor Octopus (Dr. Otto Gunther Octavius), also known as Doc Ock for short, is a fictional character appearing in American comic books published by Marvel Comics. A highly intelligent and somewhat stocky and myopic mad scientist who utilizes four mechanical appendages for both movement and combat, the character debuted in The Amazing Spider-Man #3 (July 1963), and has since been featured as one of the most enduring foes of the superhero Spider-Man, which earned him a position as one of his archenemies. Doctor Octopus is notable for forming and leading the first supervillain team to oppose Spider-Man: the Sinister Six.
While usually portrayed as a supervillain, Doctor Octopus has also been occasionally depicted as a conflicted anti-hero and ally of Spider-Man, under the identity of the Superior Spider-Man. The first appearance of the Superior Spider-Man was briefly in Daredevil vol. 3 #21 (December 2012), with a full appearance in Avenging Spider-Man #15.1 the same month. In 2013, Marvel launched a 45-issue Superior Spider-Man comic book series, which saw Octavius taking the mantle of the Superior Spider-Man and struggling to become a hero after the original Spider-Man's death in "Dying Wish".
Source: Wikipedia, "[en.wikipedia.org/wiki/Doctor_Octopus Doctor Octopus]", available under the CC-BY-SA License.