He is a highly intelligent, myopic, and stocky mad scientist who sports four strong and durable appendages resembling an octopus's tentacles, which extend from his body and can be used for various purposes.

Comics journalist and historian Mike Conroy writes of the character: "Created by Stan Lee and artist Steve Ditko, Doc Ock, as he became known, has become one of the web-slinger's most persistent, enduring, and dangerous foes.

Due to his mother's insistence and her disgust towards men who worked in common manual labor, Octavius was determined not to become like his father and threw all his efforts into his education, regularly scoring top marks.

With the death of his mother and Mary Alice Anders out of his life, Octavius' disposition towards nearly everyone became mean-spirited, and he had become more distracted from paying attention to detail and safety precautions in his work.

[18] His co-workers often called him "Doctor Octopus" behind his back, a pun on his actual name inspired by the four-armed apparatus; he was aware of this insult, but he barely cared.

[52] Octavius unsuccessfully tried to form and lead another version of the Sinister Six, because Captain America's Secret Avengers managed to defeat the villainous group, although Doctor Octopus himself eluded authorities.

[54] When Doctor Octopus learns that he is dying due to the years of punishment his body took in his villainous career, facing superhuman foes when he is fundamentally human once getting past the tentacles, he becomes increasingly despondent and brazen in his final plans.

Intending to leave a lasting legacy, he attempts to exert control over New York City by using his newly minted Octobots, but while he consciously intends to help, his subconscious drives him to turn the city's resources against Spider-Man, and he also targets May Parker aggressively (deeming her guilty of being due to marry J. Jonah Jameson's father J. Jonah Jameson, Sr.), subtly disrupting the planned marriage.

[55] In his desperate attempts to prolong his life, Octavius reforms the Sinister Six, wishing to acquire Menace's unborn son, hoping to synthesize a pure strain of the Goblin Serum,[56] only to be thwarted again by the efforts of Spider-Man and the guilty conscience of the Lizard,[57] reigniting his bitterness towards his foe, but gaining a grudging acknowledgment of his abilities.

[66] All this careful preparation came to fruition during the "Ends of the Earth" storyline,[67] where the apparently mismatched pieces of technology stolen are used to build a satellite net, the Octavian Lens, able to alter the world's climate by enhancing or smothering solar rays.

Doctor Octopus at first claims to have a benevolent intent, wishing to halt the greenhouse effect in exchange for gratitude and recognition,[68] but he is soon exposed by Spider-Man (having enhanced himself with new technology created be Horizon Labs),[69] the Black Widow and Silver Sable, who provoke him into revealing his real plan: immolate a great part of the entire population to prevent anyone from surviving his impending death, having the survivors remember him in perpetual fear and awe.

[71] Spider-Man then roughly defeats him, in retaliation for Silver Sable's death, openly mocking and berating his efforts by claiming that, because of the Octavian Lens' destruction and his declining health, he is now going to die alone, forgotten and without a legacy.

Distraught, Octavius (in a sudden surge of empathy for his sworn nemesis) vows to steer himself away from villainy and accepts Peter's dying wish of having a Spider-Man protect New York.

[77] However, he soon finds himself the target of several villains, such as an Octavius-tech enhanced Stilt-Man,[78] Boomerang, Overdrive, the Shocker, the Speed Demon, the new female Beetle, and the Living Brain,[79] all of them trying to take over the place left by the seemingly-dead Doctor Octopus and his Sinister Six.

[88] While Octavius has developed more detailed resources than Peter possessed as Spider-Man, such as creating a small army of Spider-bots and Spiderling allies to assist him, as well as helping Cyclops trap the body-hopping mutant Malice in a specially-designed containment unit,[89] he continues to resort to more questionable methods, such as killing Alistair Smythe,[90] and blackmailing Jameson into giving him free rein in New York by threatening to expose the fact that Jameson asked him to do this.

[96] Peter finds that Octavius's delete has left him with very few memories of his own, but after realizing those he still has are the ones that define him, vows not to give up, and that he will regain control of his body.

[94] Trapped in the future, he attempted to return home by creating a dimensional portal, but found himself travelling to various alternate universes – including one where Spider-Man joined the Fantastic Four and a variation of the House of M – where all the Spider-Men were dead.

[106] As part of the All-New, All-Different Marvel event, Otto Octavius is still dead but a copy of his consciousness is shown to be inside the Living Brain where he is still in love with Anna Maria Marconi.

[107] Following the events of Spider-Verse, Otto Octavius had backed up his consciousness in one of his gauntlets (the Superior Spider-Man's web-shooters) that slept for 100 days using the technology he acquired from 2099.

After eliminating the copy of Peter Parker's consciousness, Doctor Octopus gains control of the clone body and emerges from the vat where he resembles his earlier appearance.

[112] When Spider-Man later infiltrates New U Technologies after witnessing video footage of one of its subjects suffering from cellular degeneration, he evades the initial security force, including the Rhino and the female Electro.

[114] While studying the clones of Kaine and Electro to perfect the Proto-Clone, Anna Maria was brought to Otto and she becomes uncomfortable when Doctor Octopus starts appealing towards his love interest.

Upon checking New U Technologies' Haven following the broadcast, Spider-Man and Anna Maria find that Ben Reilly, Doctor Octopus, and Gwen Stacy have been seemingly reduced to dust.

[127] After Spider-Norman and Spiders-Man sundered Earth-616's connection to the Web of Life and Destiny, Octavius seemingly betrayed Ben, giving him to the Inheritors in exchange for the other Spiders being left alone.

Octavius, Anna Marie, and the Living Brain attempt to use the cosmic energies left over from the fight with Terrax to travel to Spider-Osborne's world, but it goes wrong and causes an explosion.

Captain America discovers that Iron Man is actually Chameleon in disguise who Doctor Octopus was going to use to take part in the mayoral election on his behalf.

[149] Two weeks later, Doctor Octopus has released thousands of his Octobots to enforce Mayor Wilson Fisk's zero-tolerance policy, effectively wiping out all crime in the city.

[154] When Spider-Man locates Doctor Octopus and his fellow captive villains Electro, Kraven the Hunter, Mysterio, Sandman, and Vulture, he discovers that the culprit behind the abduction was Ultra Living Brain.

[volume & issue needed] Doctor Octopus has begun wearing a full-body armor suit due to an illness caused by the amount of punishment he has sustained over the years, made even worse by the fact that his ability to take damage is still at a human norm, even if he can deliver a superhuman level of punishment; he relies completely on his arms to prevent opponents with superhuman strength getting in close enough to damage his relatively unfit physical form even before his illness.

The adamantium in his tentacles made besting Iron Man in combat possible, tearing the hero's armor apart with a defeat so harsh that Tony Stark began to doubt his abilities almost enough to allow his persistent problem with alcohol abuse to flare up.