Otto Octavius was a brilliant atomic researcher who designed and constructed a chest harness to which four artificial tentacle-like arms were attached. This harness enabled him to manipulate radioactive substances from a safe distance. In a freak laboratory accident, the scientist was bombarded with radiation. The accident bonded his harness to his skin and nervous system and drove the scientist criminally insane. Octavius found that he could control his arm mentally rather than by the mechanical controls. Calling himself by his laboratory nickname, "Doctor Octopus" has tried to amass wealth and power through a variety of criminal activities. After many defeats at Spider-Man's hands, Doctor Octopus activities have expanded to include destroying the wall-crawler as well. Eventually, surgery removed the harness from Octavius' body, but he still retains mental control over his arms.