James Shooter and Al Plastino introduce the Parasite in Action 340 (Aug. 66).
Jensen, the man who will become the Parasite, gets only the briefest introduction. He doesn’t even get a first name (or possibly a last, hard to tell.) All we really know of him is that he is a lazy lab assistant, who doesn’t pay attention to warnings.
In his fourth panel, he just opens a container of radioactive materials. Why not? What could happen? Aside from turning into a purple, skull-faced, energy draining monster.
The Parasite can draw energy off of anyone, although the story never makes it clear if those people he drains are left dead.I’m fairly certain that they are. But the energy of a human does not last very long, and the Parasite weakens. When Superman flies near, he gets a big energy burst, and realizes that Superman is the meal he needs.
To his good fortune, the Parasite happens to be on the street as Clark Kent and Lois Lane are passing. The Parasite feels the energy boost again, as Clark collapses. Parasite now knows who Superman is.
The information does not prove very useful, though. The Parasite’s plan to use his knowledge as a threat does not take into account that anyone close enough to hear him has already been rendered unconscious by his draining. Superman has a very hard time with the creature, as he loses not only his strength to him, but vision powers as well, finding himself on the receiving end of heat vision.
In the end, Superman does not even defeat the Parasite, except in a very passive way. His energy is so great, it’s more than the Parasite can absorb, and the creature explodes.
That’s far from the end for this character. The Parasite returns a couple of years down the road.