The adult birds of Blackwater Chicken are similar in male and female, and the female is slightly smaller. The forehead nails are bright red with rounded ends. The head, neck and upper back are gray-black, the lower back, waist to tail are covered with feathers, and the wings are covered with dark olive brown. The flight feathers and tail feathers are dark brown, and the outer limbs and wings of 1 primary flight feathers are white. The lower body is gray-black, gradually shallowing backward, and the tip of the feather is slightly white: the tip of the lower abdomen is white, forming black and white patches; Wide white stripes on both sides; The feathers under the tail are black in the middle and white on both sides. Underwing feathers and axillary feathers are dark brown, and feather tips are white. Young birds have brown upper bodies and dark brown flight feathers. The head and neck are brown, the chin and throat are gray, the chest is brown, and the back chest and abdomen are gray.

Iris red, mouth yellow-green; Deep blood red from the root of the upper mouth to the frontal plate; The bottom of the lower mouth is yellow. The end of the frontal plate is curved, only reaching the forehead. The feet are yellow-green, and there is a broad red band on the exposed upper tibia. The front and sides of the exposed part of the tibia are orange-red, and the back is dark reddish brown. The front end of tarsometatarsal is yellow-green, and the back end and toe plate are green. The claws are yellow-brown.

Size measurement: weight ♂200-340g, ♀141-400g; Body length ♂240-345mm, ♀ 250-325 mm; Mouth peak ♂24-32mm, ♀ 21-31mm; Wing ♂ 143- 174mm, ♀140-1mm; Tail ♂53-77mm, ♀ 61-80 mm; Tarsometatarsal ♂43-54mm, ♀ 36-52 mm (Note: male-♂; Female-♀)