Emperor moth is a European moth that lives in open, poorly drained areas known as moors. The male is slightly smaller than the female, with a wingspan of 22/3 inches (6.8 centimeters) compared to the females’ 3 inches (7.8 centimeters). The male moth has rich, chestnut markings. It flies during the day and has large feathery antennae used to detect the scent given out by the female. The females are gray and fly only at night. Both male and females have eyespots on each wing.
The caterpillar of the emperor moth is large, with green and black coloring. It has hairy, wartlike growths that may be pink, yellow, or black. The pupa is contained in a brown, bottle-shaped cocoon.