Saprotroph
Organism that feeds on the excrement or the dead bodies or tissues of others. They include most fungi (the rest being parasites) many bacteria and protozoa animals such as dung beetles and vultures and a few unusual plants, including several orchids. Saprotrophs cannot make food for themselves, so they are a type of heterotroph. They are useful scavengers, and in sewage farms and refuse dumps break down organic matter into nutrients easily assimilable by green plants.