The ethilia longwing is a brush-footed butterfly (family Nymphalidae) with an average wingspan of 6-7cm. In this family the first pair of legs is reduced and non-functional. The forewings are usually orange in colour with four black spots and black on the edge of the wings. Their orange hindwings display a pair of prominent black stripes. Larvae (caterpillars) can grow up to 1.7cm, and appear to be white, with black spikes and an orange head.