Calephelis nemesis, commonly known as the Fatal Metalmark, is a small and intricately patterned butterfly in the family Riodinidae. Like other metalmarks, it is notable for its subtle metallic sheen, often appearing coppery or bronze in the light. The wings are typically orange to reddish-brown, crossed by numerous fine, dark lines and bands that create a delicate, almost engraved appearance. This species is found in Mexico and Central America, where it inhabits forest edges, clearings, and brushy habitats. It tends to fly low and slowly, often settling on leaves or the ground, and may return to the same perch repeatedly.