The nilgai (Boselaphus tragocamelus), sometimes called nilgau, is an antelope, and is one of the most commonly seen wild animals of central and northern India and eastern Pakistan; it is also present in parts of southern Nepal. The mature males appear ox-like and are also known as blue bulls. The nilgai is the biggest Asian antelope.
Nilgai stand 1.2-1.5 meters (4–5 feet) at the shoulder and are 1.8-2 meters (6-6.6 feet) long. Their tails are 40-45 centimeters. Mature nilgai typically weigh 120-240 kilograms.
Nilgai antelopes are found in the north Indian plains from the base of the Himalayas in the north, down to the state of Karnataka in the South, and from the Gir forest and from all along the entire eastern length of Pakistan and over across the border of Rajasthan in the West to the states of Assam and West Bengal in the East; in Nepal, they occur patchily in the southern lowlands. The population density in central India is 0.07 animals per square kilometer.