Coprinopsis lagopus is a species of fungus in the family Psathyrellaceae. Until 2001, the species was known as Coprinus lagopus; advances in the understanding of phylogenetic relationships between the various coprinoid species led to a major reorganization of that genus. It is a delicate and short-lived fungus, the fruit bodies lasting only a few hours before dissolving into a black ink – a process called deliquescence. The vague resemblance of the young fruit body to