a mushroom is a kind of fungus & in the food chain process fungi have the role of decomposer -> in the poison equal log toadstool have the nuts of decomposer in the food chain process mushrooms have the role of decomposer  in the poison equal log toadstool have the nuts of decomposer & if something has the role of something else then that something is an example of that something else -> an example of a decomposer is a mushroom