Nandi, or Nandin, is a white bull constantly associated with Lord Shiva. It is Shiva’s vehicle. A murti of Nandi is found in almost all Shiva Temples. The bull is seated in front of the sanctum sanctorum (garbhagirha) and is the guard or door keeper or gate keeper.
Puranas associated with Shiva, details about the role played by Nandi as guard. He is also the chief of Shiva’s ganas (attendants) and Nandishvara is another name of Lord Shiva.
Nandi means ‘causing gladness.’ Nandi is always represented as quiet and benign. He also symbolically represents sexual energy tamed by Shiva. The disciplined bull, which is calm and docile, symbolizes Dharma, an image of controlled power. He is also considered to be the guardian of four-legged animals.
The image of Nandi is often placed outside the sanctum sanctorum facing the Linga or the murti of Shiva. Sometimes the images are found on the corners of the sanctuary of Shiva temples.
In North India, Shiva is also depicted as dancing on the bull. It is also said that Shiva gave the first lessons in dancing to Nandi. Due to this Nandi is also referred as Tandu. In Shiva myths in Bengal, Nandi is shown dancing with Shiva and occasionally he beats the drum.
There are several instances in the Puranas when Nandi was cursed by Shiva and Parvati. Nandi would be guarding the doors when Shiva and Parvati are in sexual union. Gods or demons would approach Nandi with the request of meeting Shiva. Nandi would sternly deny them but they will find some method to enter the room and disturb the amorous couple. In the end, Nandi will be cursed but soon he will regain his position through the austerities performed in the cursed state.
The two of the largest Nandi statues in India are found in the Halebid Shiva Temple in Karnataka. One of the famous Nandi Statues in India is at Chamundi hills in Mysore, again in Karnataka.