Scavenger

Scavenger
An animal (such as a vulture or coyote) that eats carcasses abandoned by predators, digs through trash cans for food, etc., true scavengers seldom kill their own prey (but many animals are not exclusively scavengers).
A chemical agent that is added to a chemical mixture to counteract the effects of impurities.Any animal that feeds on refuse and other decaying organic matter.Organisms that feed on material left over by other organisms, an example being the buzzard that feeds on leftover material left by the carnivores (e.g. a lion).