Parasite
The purple-skinned villain who is able to absorb the powers and personalities of other life-forms. He first encounters Superman after being transformed from a janitor named Maxwell Jensen through exposure to an extraterrestrial waste material (Act No. 340, Aug 1966: "The Power of the Parasite!").
Later exploits chronicle how Jensen's body could reconstitute itself over time, and that there were definite limits to how much superhuman energy he could drain from Superman. Parasite was directly involved in creating a derivative Solomon Grundy based on spores left behind in the Metropolis sewage system by the Grundy of Earth-Two. Jensen was one of the few adversaries of the Man of Steel to know his secret identity, which he often exploited although never revealed to the general populance nor towards fellow villains.
