The nilgai or blue bull is actually a species of antelope, commonly seen all over north India.  It looks like a cow, hence its name (nil means blue, gai means cow). The blue bull is regarded as a bovine animal, leading to the local belief that the nilgai is a cow and hence sacred.

The gods of the Veda were called bulls for their superior power and abilities. The Vedic status of the bull was inherited by Nandi, the companion and vehicle of Shiva in later literature.

Two of the Sapta Matrikas (Seven Mothers), aspects of Durga or Shakti, Maheshwari and Varahi have bulls as their vehicles.

The bull is the emblem of Adinatha or Rishabhanatha, the first Jaina Tirthankara.

 According to the Zend-Avesta, the bull is an incarnation of Verethraghna, the Iranian version of Vritrahan, another name for Indra the killer of Vritra, demon of drought.

In Karnataka, Nandi is known as Basava, and the famous Bull Temple of Bangalore is situated at Basavangudi.

Biroba or Viroba the bull is worshipped by the Dhangar, a nomadic shepherd community of Satara, Sangli, Pune and Kolhapur districts of Maharashtra.