The Northern Alligator Lizard is a small lizard that resembles a miniature alligator, from which the species gets its common name. Adults average 9.5 cm in length with females being slightly larger than males (Rutherford 2004). Males have relatively wider heads than females, possibly for use during mating (see Reproduction below). Their background colour is grey or tan marked by dark blotches, and their bellies are white to gray (Fitch 1935). The young have a broad, bronze stripe on their side. Adults have a distinctive fold of skink that runs along their sides; it helps the body to expand when the lizard inflates itself with air or is distended by eggs or food.