Cornufer paepkei is a species of frog in the family Ceratobatrachidae, endemic to rainforest habitat. Scientitsts know it exclusively from the type locality: the Fakfak Mountains in Indonesia, between 400 and 860 meters above sea level.
The adult frog measures 21.6 to 31.4 mm in snout-urostyle length. Its voice sounds like a "low, short creak." There a small amount of webbed skin on its feet. The frog is yellow-brown in color with dark brown or black patterning. There are two yellow-white lines from its nose to its hind legs. The backs of the legs are red-brown in color. Other parts of the legs are almost purple. The ventrum is off-white.[1]