One of the most familiar butterflies in the eastern United States. The Eastern Tiger Swallowtail is large and slow moving. The male is yellow with four black “tiger stripes” on each forewing. Females may be either yellow or black, making them dimorphic (two or more different forms). The outer edge of the forewing is black with a row of yellow spots and the veins are marked with black. The hindwing of both female forms has a row of striking blue chevrons and an iridescent blue wash over parts of the interior hindwing. The inner margin of the hindwing has small red and blue spots.