Eryphanis automedon, the Automedon giant owl, is a species of butterfly belonging to the family Nymphalidae.
Eryphanis automedon has a wingspan reaching about . In males the dorsal sides of the wings show night blue iridescent patches, extending from submedial to postmedial areas, with well defined borders separating the non-iridescent sections. Ventral sides vary from faded brown to caramel color, with various eyespots. The female wingspan is slightly larger, with a slightly different wing color pattern.
This butterfly can live up to six weeks and flies in the dark forests of Latin America. It is a fast flying butterfly. The caterpillars are cryptically colored and feed at night on Poaceae host plants (mainly bamboo leaves), of which the elongated chrysalis mimics the appearance of a dried leaf.
This butterfly is native to South America. It is present from Venezuela to the Guianas and Brazil and from Colombia to Paraguay, at an elevation of above sea level.
The following subspecies are recognized: