From DC Database
Raymond Maxwell Jensen
Maxwell Jensen; Larcon P. Leech 
Raymond Maxwell Jensen was a lowlife who got a job as a plant worker for a research center. Believing that the company payrolls were hidden in storage containers, Maxwell opened one and was bombarded with energies from biohazard materials (which was actually waste collected by Superman when he traveled into outer space), which transformed him into a purple skinned, parasitic entity, becoming the Parasite; any time he touched someone, he could absorb their physical and mental properties. Touching Superman would instantly absorb a sizable fraction of his superhuman powers (it was established early on that he is not capable of acquiring the whole of his powers). On one occasion, while attempting to absorb a greater portion of his adversary's powers than previously, his body disintegrated for a period of time due to the pressure to his cells. Despite these abilities, the Parasite became depressed because he could no longer embrace his wife and children. The Parasite made a number of reappearances before the Crisis on Infinite Earths, yet he never successfully found a means to permanently defeat Superman. Despite this, he had knowledge of his foe's alter ego and often used this to attack Clark Kent. Gaining sizable intellect from his multiple encounters with Superman, Parasite devised the means to reanimate dormant plant remains left behind from the Earth-Two supervillain Solomon Grundy, creating a newer and stronger version of the creature to plague his adversary. On another occasion, Parasite devised the means to transfer the powers of the hero Air Wave to the young hero's adversary Davy Jones temporarily.
Parasite was one of the main characters in the second Marvel/DC crossover between Spider-Man and Superman (Marvel Treasury Edition #28). In this story, he was recruited by Doctor Doom as an agent in Doom's latest plan to conquer the world by wiping out all power sources but his own fusion reactor. Doom claimed that he needed the Parasite to function as an invincible bodyguard, capturing the Incredible Hulk and Wonder Woman and giving the Parasite a harness that would allow him to retain their powers for prolonged periods. However, Doom's true intention was to kill the Parasite by allowing him to absorb so much power that his cells would burst, giving him access to a crystal that would allow Doom to perfect the reactor. This plan was thwarted when the Parasite briefly absorbed Spider-Man's powers, causing his borrowed spider-sense to alert him to Doom's treachery and turn on Doom, although he was subsequently defeated by Superman using a gauntlet of Doom's that prevented the Parasite from absorbing his energy.
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