Shiva's constant companion actually is Shivaansh and he too considered a Shivavataar. Once, the Pitra's of shilaad Sage were constantly hungry and thirsty so they requested Shilaad to create son who would serve them. The kind sage agreed and worshipped Indra for many years. Indra appeared to grant him a boon. The Sage then asked him to grant an immortal Ayonij (not born from womb) son. Indra requested the Sage to change the demand of this boon since he nor could Brahma or Vishnu fulfil this demand because they too were created by Shiva. Only Shiva had the power to grant this boon. He requested the Sage to worship Shiva instead. So Shilaad Muni once again started meditation for Shiva's boon. He was so engrossed in this worship that he forget his hunger and thirst. He appeared like a skeleton, for thousands of years he meditated. Ants and insects crawled over him and bit him. An ant hill type mound was boon, he had to be physically touched to get his attention. The Sage cam out of his meditation and was granted his boon that Shilaad would get a son with Qualities of Shiva.
The overjoyed Sage sat to perform a Yagya. Form its bright frame appeared a divine child with divine Qualities. Shilaad named the child as Nandi as he had brought Anand or happiness in their lives. But one fine day Nandi started looking like an ordinary person as his divine look disappeared. Everybody was disheartened. Once two tapasvi's named Mitra and Varun came to Shilaad's hermitage. They predicted that this son would not survive for more than a year. This disheartened Shilaad was now worried. But Nandi promised to him that he would worship Shiva to get back his age.
He left for the forest and performed severe Tapa towards Shiva continuously chanting the Rudra Jaapa. Shiva obliged and appeared before him. Before granting the boon he blessed Nandi by saying that from today Nandi would always stay with him as a son. He called all the Gana's and anointed Nandi as the Ganeshwar of all his Gana (Chief of all Ganas). Even devtas were present there to witness this. He then took a little Ganga water from his hair and sprinkled in around. Immediately it turned into seven Rivers (Jatodka, Tristotta, Vrishdhwani, Swarnadka and Jambu River) On its bank is situated the Japeshwar tirth. Shiva told him that Mitra and Varun were sent by him. He then granted the boon of immorality to Nandi. Nandi married Suyasha in the presence and with the blessings of all Devtas.
