The Vietnamese Langur, also known as the Delacour's langur, is a critically endangered primate native to northern Vietnam. This species is characterized by its distinctive black fur, white facial markings, and a long tail. They primarily inhabit limestone forests and are known for their social behavior, living in small groups. These langurs primarily feed on leaves, fruits, and flowers, playing a vital role in their ecosystem by aiding in seed dispersal. Conservation efforts are underway to protect their habitat and increase their population, as they face threats from habitat loss and hunting.