A restoration of the skeleton of Cacops by Samuel Wendell Williston, who named the genus in 1910.
It was about 40 centimetres (16 in) long and well adapted to a terrestrial lifestyle, with a heavily built skull, strong legs, a short tail, and a row of armor plates along its back. Compared to other dissorophids, it has an enormous otic notch in the back of the skull enclosed with a bony bar, indicating a large eardrum. Edwin Colbert suggests that perhaps it was a nocturnal animal like modern frogs. Cacops was first named by American paleontologist Samuel Wendell Williston with the description of the type speciesC. aspidephorus from Texas in 1910. A second species, C. morrisi, was named from Oklahoma in 2009.