Fungi are eukaryotic organisms that are unicellular or multicellular.
Fungi that get nutrition from dead organic matter are called saprophytes (e.g., Penicillium).
Parasitic fungi (Puccinia) depend on living plants and animals for nutrition.
Some fungi obtain nutrition by forming a symbiotic relationship with algae or plants (e.g., lichens and mycorrhiza).
They lack chlorophyll pigment because of which they cannot produce food on their own, therefore they depend on other organisms for deriving nutrition. Hence, we can say that all fungi are heterotrophic in nature.