Males of this large, robust frog are slightly larger than females; they attain a maximum snout-vent length of 18.0 cm (7.1 in), whereas the maximum length in females is 17.6 cm (6.9 in). The body is robust; the head is large with an acutely rounded snout and prominent tympanum. The skin on the dorsum and venter is smooth, and a prominent dorsolateral dermal fold extends from the orbit to the groin. The fingers and toes are long with slender tips and lack webbing. Breeding males have greatly swollen forelimbs and one large, pointed, black spine on the inner surface of the thumb and two black spines on each side of the chest. The dorsum is tan to reddish brown with broad, reddish brown marks on the body between the yellowish tan dorsolateral folds. The dorsal surfaces of the limbs are tan to reddish brown with narrow transverse brown bars. The upper lip is tan with a brown margin and dark brown triangular spots. The venter is cream with bold dark brown to black mottling, especially on the belly and hind limbs. The iris is bronze.