Respected scientist Otto Octavius was working for Osborn Industries on a S.H.I.E.L.D. funded U.S. government project to create a super-soldier serum, the Oz Compound; he was also an industrial spy for Osborn’s Rival Justin Hammer. After the Compound accidentally mutated teenager Peter Parker, Otto’s employer Norman Osborn decided to test a sample on himself. He had Otto supervise the procedure, but an explosion destroyed the lab, and the mechanical arms Otto wore for delicate experiments were fuse to his skin. Otto eventually awoke in government custody, his mechanical arms still attached so their grafting could be studied; he went beserk, escaped, and slew the new occupant of his old home. Irrationally blaming Hammer for his condition, Otto attacked Hammer’s “Big Apple Energy Dome” facility, soundly defeating Spider-Man in the process. Days later, Otto attacked Hammer’s secret, illegal New Jersey genetic facility, murdering its scientists, calling in the press to observe, and terrorizing Hammer until he suffered a heart attack. Before he could do any further damage, Spider-Man arrived. Better prepared this time, the arachnid hero turned Octopus’s own electrical attack against him, pounded Octopus into unconsciousness and ripped out one of the villain’s tentacles.

S.H.I.E.L.D. captured Otto, removed his tentacles, and incarcerated him alongside others genetically enhanced criminals (including Osborn, the Green Goblin) for study and interrogation. Otto seemingly co-operated until he remotely activated his arms, killed his captors and freed his fellow inmates. As de facto head of the escapees, Osborn had Otto breach S.H.I.E.L.D. security and deactivated the defenses of their Triskelion HQ. They kidnapped Spider-Man and blackmailed him into joining their attack on the White House, but the Ultimates recaptured them and the Wasp defeated Doctor Octopus. Once more stripped of his arms, he was incarcerated in the super-prison known as The Raft.