God Vishnumaya is akin to Sastha, Muruka or Vikhneswara but this Sivanandana (The Child of Siva) is worshiped not in common but by a special kind of devotees who need extra ordinary result. "Vishnumaya is easily pleased and humane" are the words of Devotees. Let us look into the glory of Vishnumaya. On his way for the divine hunt Lord Siva happened to hear a sweet voice in the jungle. He was surprised to find that it belonged to a tribal girl, "Koolivaka" - a girl of immense beauty. The solitude in that forest area called Koolivanam, and the wild beauty of the forest girl, made the Lord lustful. He informed Koolivaka of his wish and told her to wait for him until he returned from his hunt.
In her previous birth Koolivaka was Mansawini, a servant in the retinue of Parvati. One day she happened to breast-feed lord vinayaka who was a baby at that time. Parvati didn’t appreciate the fact of a servant breast-feeding her baby. She cursed manaswini that she would be born in a chandala(outcaste)family. When Parvathi's anger subdued, she took pity on Manaswini. Devi Parvathi blessed her that although she be born as a chandala she would get the opportunity to breast-feed the son of Shiva. Devi disclosed that it was the pre-ordained fate that made possible her meeting with Lord Shiva and his passion for Koolivaka. She told the girl that she herself would take on the form of Koolivaka and deceive the Lord Shiva. She also informed Koolivaka that the son born from such a union would be the killer of Jalandhara, a powerful Asura. A child with divine power was born through this holy union. Siva and Parvathy appeared in front of Koolivaka and deputed her to foster the child. After living with Koolivaka for some years the child became mature enough to know the detail of his real parents. Then Sivanandana proceeded to the abode of Siva rode on a cute Buffaloe blowing his favorite Eezhara. When he was not allowed entrance into the abode of Siva, Sivanandana assumed the form of Vishnu. Thus Sivanandana was known as 'Vishnumaya.'