Mainstream Earth-616 biography:
Otto Octavius had a turbulent upbringing. His father, a factory worker, was abusive and violent towards both Otto and his mother, leading Otto to be shy and reclusive in school. However, at his mother's insistence, he was determined not to become like his father and threw all his efforts into his education, regularly scoring top marks. It was hinted that he was a low-level telepathic mutant whose powers emerged at puberty; this mutation may have been responsible for giving his father an aneurysm as his father went to beat him. His father's death in an industrial accident pushed Otto further towards the study of, and obsession with, physical science.
Before his transformation into the megalomaniacal archenemy of the web-slinger, Otto was a brilliant and respected nuclear physicist, inventor, and lecturer. He became the youngest person to serve on the National Board of Nuclear Science. He designed a set of highly advanced mechanical arms to assist him with his research into atomic physics. The tentacled arms were resistant to radiation and were capable of great strength and highly precise movement. They were attached to a harness that fit around his body.
During an accidental radiation leak that ended in an explosion, the apparatus became fused to Octavius' body. It was later revealed that the radiation (or possibly his own latent mutation) had mutated his brain so that he could control the movement of the arms using his thoughts alone. The tentacles have since been surgically removed from his body, although Octavius retains the power to control them telepathically from a great distance. The accident also seemingly damaged his brain (although it was later suggested that what was interpreted as brain damage was in fact his mind rewiring itself to accommodate four extra limbs), and the scientist turned to a life of crime.
|Classic Doctor Octopus|
|Chapter 1 Dr. Octopus|
|Dr. Octopus Noir|
|Ultimate Dr. Octopus|