The term "deadly fungus" refers to a type of fungus that can cause severe illness or death in humans, animals, or plants. This kind of fungus is often characterized by its ability to produce toxic substances that can harm living organisms and disrupt ecosystems. Some examples of deadly fungi include the notorious "white rot" fungi which are capable of degrading lignin in wood, as well as various species of mushrooms such as Amanita phalloides (the death cap) or Inocybe aeruginascens (the blue leg mold), both of which can cause severe poisoning if ingested.