The sambar deer (Rusa unicolor) is the largest Oriental deer with adults sometimes weighing as much as 546 kilograms. The hairy coat of the sambar deer is generally consistent in color around the body, but can vary from yellowish-brown to almost dark grey. There is also variation in the color of the different sub species.
The sambar deer is an herbivore, with a diet consisting of a variety of plants. It grazes or browses on a range of plant species depending on forage availability at the time, and this allows it to have great habitat flexibility.
The sambar deer is fairly shy and is mainly active at twilight or at night. This species are very alert and silent, and will freeze instantly if disturbed. The sambar deer is one of the few deer that attacks sizeable predators, and it prefers to hold confrontations in shallow water.