Joshua Michael Allen was a bike messenger for a local Metropolis package company. Upon running into a giant booger monster as he described it, Joshua broke from how much he hated living in Metropolis and attacked the monster with his bike. While he was in the grip of the monster he grabbed an electrical cable and plunged it deep into the monster.
After waking up in the hospital with a broken leg, Joshua lost his job and girlfriend. S.T.A.R. labs called him in to go over tests to see if encountering the monster had any effect on his body. During the procedure, Joshua absorbed the life force of the doctors and was transformed into the Parasite.
With such hunger, Joshua tried to feed as much as he could. He killed many of his co workers and his ex-girlfriend. But he couldn't handle starving everyday. He tried killing himself by jumping off Suicide Slum, a building notorious for suicide jumpers. But at the last second Superman saved him. But when the two made contact, Parasite grew stronger and bigger than before. Parasite demanded more and faced Superman in combat. But Parasite used too much of his newly acquired heat vision and drained himself of all his energy. Superman sent him to jail only to escape. Now Parasite vows to have the best meal he has ever had.