The Apollo is a beautiful white butterfly, decorated with large black spots on the forewings and red eyespots on the hindwings. These striking red eyespots can vary in size and form depending on where the butterfly comes from, and the bright red colour often fades in the sun, causing the eyespots of older individuals to appear more orange. The wings are shiny, with slightly transparent edges, and some individuals are darker (melanistic); a general phenomenon common in many butterflies. The caterpillars are velvety black with orange-red spots along the sides. As well as being a great deal of individual variation in the appearance of the Apollo butterfly, a number of subspecies have also been described.