The Cat Ba langur is recognizable by its golden head and dark body. It lives in forest on the limestone hills of Cat Ba Island in Vietnam and feeds mainly on leaves.
The body is dark chocolate brown to black, with a silver-haired V running from the thighs to the base of the tail. A yellowish-white to golden crest on the head darkens toward the shoulders.
Leaves form the main part of its diet, with shoots, fruit, flowers, and bark also eaten. Groups generally consist of one adult male, several females, and offspring.
An extinction-risk assessment has not been added yet.