When adult, the elephant hawkmoth has a khaki or yellowish to greenish upper portion of head, abdomen and thorax, with bright-pink patches. The wings are khaki with black and pink markings on the upper side, as well as a pink fringe. The underside of the wings show the same colors, but are often lighter and without the black markings. The wingspan is about 2 inches to 3 inches. Caterpillars are brownish-gray with black markings and measure about 3 inches in length.
Like other moths, the elephant hawkmoth passes through a metamorphosis process during its life cycle. Adults emerge in June, when females lay pale green eggs on the leaves of the willowherb, Epilobium hirsutum. Caterpillars are able to retract their head and expand the first segments of their body when feeling threatened. This gives them a snake-like appearance and keeps predators away. In the beginning of fall, caterpillars enter a new developmental stage, the pupa.
Elephant hawkmoths are more active at night. Like other hawk moth species, they have a rapid wing-beat, which produces a whirring sound. Adults feed on the nectar of honeysuckle flowers, with long tongues. The two subspecies of elephant hawkmoth are
Deilephila elpenor macromera, which is found in Bhutan, Myanmar, India and China, and Deilephila elpenor elpenor, which is more common and widely spread in Europe and Asia.
Elephant hawkmoths have a large number of special light sensor in their eyes, which enable them to distinguish colors at night. Like many other insects, elephant hawkmoths have compound eyes made of several units called ommatidium. While most butterflies have two to six light sensors in each ommatidium, elephant hawkmoths have about nine light sensors in each eye unit.