The Serpentine Webworm Moth has a wingspan of 1 to 1.25 inches. The forewing is light brown with tan and dark brown markings. The subterminal line is dark brown underlined with tan loops. Similar species are separated by the light patch between 2 brown median spots and the distinctive light patch in the fringe at the anal angle. The hindwing is similar to the forewing but it the subterminal has tan loops above and below the line. Besides the typical light form there is also a dark brown form. The larva is green and yellow with a reddish head and grows to about 1 inch.