Nandi is the bull vahana (mount) of the Lord Shiva. He is also the guardian deity of Kailash, the abode of Shiva. Almost all Shiva temples display stone images of a seated Nandi, generally facing the main shrine.
Nandi is also known as Nandikeshvara or Nandideva. The word nandi means happy, joy, and satisfaction.
As per Shiva Purana, Nandi was born from a yajna performed by sage Shilada. Nandi grew up as an ardent devotee of Shiva and he performed severe penance to become his gate-keeper, as well as his mount. According to regional legend, this site is identified with the Tripur Tirth Kshetra in present-day Nandikeshwar Temple, in Jabalpur, Madhya Pradesh.
Iconography of Nandi
The Agamas describe Nandi in a zoo-anthropomorphic form, with the head of bull and four hands, with Mriga (antelope), Parasu (axe), Gada (mace), and abhayamudra.
In his mount form, Nandi is depicted as a seated bull in all Shiva temples, all over the world.The white color of the bull symbolizes purity and justice.