The Gayal (Bos frontalis) is a large cattle that is the domesticated form of the Gaur. They are most commonly found in Bangladesh and northeast areas of India such as the state of Arunachal Pradesh. In the Adi language, gayal are called eso; they are called subu by the Apatani and Nishi tribes, or often referred to as "mithun" or mithan.
In his first description of 1804, Aylmer Bourke Lambert applied the binomial Bos frontalis to a domestic specimen probably from Chittagong.
In 2003, the International Commission on Zoological Nomenclature fixed the first available specific name based on a wild population that the name for this wild species is valid by virtue of its being antedated by a name based on a domestic form. Most authors have adopted the binomial Bos frontalis for the domestic species as valid for the taxon.
To the Adi people (Bangni-Bokar Lhobas), the possession of gayal is the traditional measure of a family's wealth. Gayal are not milked or put to work but given supplementary care while grazing in the woods, until they are ritually slaughtered or killed for local consumption.
The gayal is the state animal of Arunachal Pradesh and Nagaland. Gayals play an important role in the social life of the people in Arunachal Pradesh. Marriages are not fixed until the bridegroom's family gives at least one gayal to the bride's household.
Gayals are left in the forest, where they usually stay within a small perimeter. Females are usually aggressive when with calves, and there are instances known when people have been severely injured after being gored by one. Male are usually more docile.