Cassionympha cassius

The Rainforest Brown (Cassionympha cassius) is a butterfly of the Nymphalidae family. It is found in South Africa, it is common in cool and moist forests, coastal and riverine bush and kloofs in the western Cape along the western coast through the eastern Cape to KwaZulu-Natal, the eastern slopes of the escarpment through Swaziland and Mpumalanga to the Soutpansberg in the Limpopo Province.

The wingspan is 34–38 mm for males and 36–42 mm for females. Adults are on wing from September to May (with a peak from September to May).

The larvae feed on Poaceae species, including Pentaschistis capensis and Juncus capensis.