Marpesia petreus, commonly known as the Ruddy Daggerwing, is a distinctive butterfly in the family Nymphalidae. It is named for its long, sharply pointed forewings, which give it a dagger-like silhouette in flight and at rest. The upper side of the wings is typically rich orange to reddish-brown, sometimes with subtle darker markings, while the overall shape is elongated and angular, unlike most butterflies. The underside is dramatically different—mottled brown and gray, closely resembling a dead leaf, providing excellent camouflage when the butterfly rests with wings closed. This species is found in the southern United States, Mexico, Central America, and South America, inhabiting woodlands, forest edges, and open areas. Adults are strong fliers, often seen gliding or darting rapidly, then perching with wings closed on tree trunks or leaves.