'India has the largest population of the Asian X. Today, there are just about 20000 to 25000 X in their natural habitat spreading across the evergreen forests, dry thorn forest, swamps and grasslands. Their prime habitats, are however the moist deciduous forests. The X population in India ranges from North-West India where they are found in Dehradun and Nainital of Uttarakhand to forest areas of Bijnor in Uttar Pradesh to the Western Ghats in the States of Karnataka, Kerala and Tamil Nadu. In Central India, their population is distributed in Southern Bihar and Odisha. In the East, they are seen in North Bengal, Assam and a few other states'. The animal 'X' referred to in this question is