Adult: Species description based on Duellman (2001) and Savage (2002). A very large frog. Males reach lengths of 106 mm. Females are smaller (to 86 mm). Adult males have prepollical spines. The skin on the head is co-ossified to the skull in large specimens. Dorsal: The color of the dorsal skin is mottled shades of brown and/or green. Some white or orangeish markings may also be present, and the thighs are barred. Dorsal coloration can change within individuals. The dorsal surface is covered with small bumps. Ventral: The ventral surface is lighter tan, with some pinkish hues on the limbs. The skin of the ventral surfaces is granular. Concealed surfaces: The rear surfaces of the thighs are mottled brown on a lighter brown background. Eye: The iris is bronze with some reddish, brownish reticulations. Extremities: The hands and feet are very large and fully webbed. The arms have distinct dermal fringes (skin folds) extending from elbow to wrist.
Habitat: Lowland and premontane forest to 1330 m. Ecology: This frog inhabits forest canopy. Call: A single "gurrrgh", like a growl, repeated infrequently (Savage 2002). Behavior and communication: Ecnomiohyla miliaria uses the extensive webbing on its hands and feet to glide through the air (Duellman 1970, Duellman 2001, Savage 2002). Type locality: Nicaragua