Source: comicsblog.fr

6. Parasite

Man, if you're a janitor for a massive corporation in the DCU, you're gonna get screwed one way or another.

Rudy Jones was a S.T.A.R. Labs janitor, until he was irradiated, because Darkseid thought it would be cool to get a new supervillain to fight Superman. As a result, Rudy became horrifically deformed and gloriously pink and gained superpowers.

His new power was the ability to leach energy and life force from his victims. He eventually discovered that he could gain the ultimate high and sate his hunger by feeding off of Superman, and that's exactly what he wants to do. Unfortunately (for him), Parasite tends to have a pattern of biting off more than he can chew (heh) and almost killing himself with energy overloads.

Parasite would make an excellent film villain, due especially to the nature of his powers. He's a perfect foe to weaken Superman without resorting to Kryptonite as a plot device. Also, like Metallo, he has some great visual design to be used.