Niphanda fusca is a parasitic butterfly primarily found in East Asian countries such as Japan and Korea. It is a "cuckoo-type" parasite of the ant Camponotus japonicus. It utilizes chemical mimicry to trick the host worker ants into adopting it while it is a third-instar caterpillar. From there, it is fed mouth-to-mouth by the worker ants as though it were one of their own young.

The butterflies of this species differ in color between the male and the female. The male has more of a purple tint with a gray underwing.

N. fusca is currently an endangered butterfly, with an alarming and rapid decrease in numbers. Many locations that have previously recorded sightings have now become areas where the butterfly is extinct. These changes, which have come about mostly in the past 40 years, have resulted from habitat changes moving away from preferred early stage succession ecosystems, as well as habitat changes due to urban development.

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