Nandi is Shiva's principle bhakt and chief of all Shiva's ganas (followers). He is a bull,and is Shiva's main vehicle (vahaan). For him, Shiva is his lord and like a father to him.
He is potrayed by Kumar Hegde.
Nandi is actually a bull,but is usually shown in his human form.
As a human,he has curly hair, bull ears, and wears a rough beige tunic along with several wooden ornaments and a necklace made out of bells.
In his true form, he is a beautiful white bull.
Nandi is quite emotional and sensitive. Whenever he sees his lord in distress or in pain, or when Shiva scolds him, he often begins to cry.
He was born to Shilad as a boon from Lord Shiva.Later, he became Lord Shiva's greatest devotee and went to live in Kailash so that he could serve his Lord.
He tried very hard to unite Sati and Shiva and often tried to convince his lord to marry her and accept her as his wife.Finally, when Sati married Shiva and came to Kailash, he tried his best to make her comfortable.
Later, he accompanied her to Daksh's yagya and also tried to stop her from giving up her life, but failed to do so. After Sati's death, he along with the other ganas destroyed the entire place.
When the grief-stricken Shiva was roaming the earth as a human after Sati's death, Nandi accompanied him and tried to convince him to come back to Kailash and become Mahadev once again. It was he, who first saw the first Shakti Peetha and told Shiva about it. Also,it was due to his efforts that Shiva became Mahadev once again.
Later,when Mahadev established all the Shakti Peethas, Shiva set out to the Amarnath Caves to meditate. Nandi tried to stop him and take him back to Kailash, but was unable to do so. Therefore, he turned into a stone bull and waited out side the cave for his lord to come out of his meditation.