Langur , common name for certain Asian and East Indian long-tailed, slender monkeys that weigh from 4 to 24 kg (9 to 53 lb). Langurs have heavy eyebrows and, often, beardlike hairs on their chins. Some are strikingly colored. Langurs are arboreal animals that live in troops and feed on vegetation. In India, langurs are considered sacred, and troops of the animals sometimes feed unmolested on crops .