It is the largest and most numerous rhino, and competes with the hippopotamus as the largest animal after the elephant. The males have longer horns and a more pronounced crest than the females. The prominent crest, located on the back of the neck behind the ears, is made of bones, muscles and ligaments which support the immense head.
It is the most sociable of the rhinos, is generally calm, and is found in mother-baby pairs, who remain together for long periods of time. Small herds are also formed by groups of up to 7 juveniles. Mature males tend to be solitary. Due to its wide and straight upper lip it is also known by the name of square-lipped rhino. One of the main threats to its population is illegal hunting for the international trade in rhino horns. The horns have two principal uses: traditional use in Chinese medicine and ornamental use.