Scavenger (noun)

1. A person or animal that searches for and collects discarded or refuse material.
2. An organism that feeds on dead or decaying matter.

Origin:

Early 17th century (as a noun denoting a person who picks up refuse in the streets): from obsolete scawage (from scaw, of unknown origin), later reinforced by scavenge.

Examples:

1. The city employed scavengers to collect the garbage.
2. The vultures were scavengers.
3. The dog was a scavenger, always looking for food.
4. The scavenger cleaned the streets.
5. The scavenger lived off the waste of others.