| Caterpillar fungus, Ophiocordyceps unilateralis, Ophiocordyceps sobolifera|
Ophiocordyceps is a genus of fungi within the family Ophiocordycipitaceae. The widespread genus, first described scientifically by British mycologist Tom Petch in 1931, contains about 140 species that grow on insects. Anamorphic genera that correspond with Ophiocordyceps species are Hirsutella, Hymenostilbe, Isaria, Paraisaria, and Syngliocladium.
One species complex, Ophiocordyceps unilateralis, is known for its parasitism on ants, in which it alters the behavior of the ants in such a way as to propagate itself more effectively, killing the ant and then growing its fruiting bodies from the ant's head and releasing its spores.