Parasite is a villain from the Superman media and is named after the fact that much like a parasite he enjoys feeding off others to enhance his own strength.
Once a janitor, Rudy Jones became Parasite by stealing from a center.
Powers and Abilities
Parasite has the ability to absorb other people's strength and power. However, this absorbed power would eventually fade. In Superman: The Animated Series, Parasite chained Superman up in the basement of S.T.A.R Labs and absorbed energy from him whenever his power got low.