Otto Octavius, later called Doctor Octopus, is the main antagonist of the 2004 superhero film Spider-Man 2 and a supporting character in the 2021 Marvel Cinematic Universe film Spider-Man: No Way Home. He was a scientist and friend of Peter Parker who later became possessed by his own malevolent mechanical arms after an experiment with his fusion reactor funded by Peter's best friend, Harry Osborn, went horribly wrong. From then onwards, Otto turned into a dangerous supervillain and the former second adversary of Spider-Man.