Naag Panchami or festival of snakes is a unique festival dedicated to honour the Serpent God or Naag Devta. Falling on the fifth day of Shravan in July/August, reverence for the cobra (snakes) are paid.
Fairly widespread before the Aryan invasion, worshipping of snakes or Naga was later incorporated into Hinduism by the Aryan themselves. Hindu Mythological books are famously filled with stories, fables and pictures of snakes.
Lord Vishnu's couch is the green, thousand-headed snake (Ananta or Sesha) who could hold up the earth. Lord Shiva wears a snake for ornamental purpose. Even Lord Krishna is called "Kaliya Mardan" to commemorate his victory over the giant snake, Kaliya.
A farmer while tilling his land incidentally killed some young serpents. The serpent took revenge by biting all members of the farmer's family except his daughter, who worshipped snakes.This devotional act of the girl resulted in revival of her family. So on the day of Naag Panchami, tilling of land is forbidden. Snake worship is however believed to have originated due to man's natural fear of reptiles.
Naga Panchami is one of the most ancient fasts in India and also finds mention in the Puranas. It is believed to be one of the most auspicious days of the entire year. According to the Bhavishya Purana, when men bathe the snakes Vasuki, Takshaka, Kaliya, Manibhadra, Airavata, Dhritarashtra, Karkotaka and Dhananjaya with milk, on the fifth day of the bright fortnight of Shriven, they ensure freedom from danger for their families. As per a legend, on the day of Naga Panchami, ploughing a field is forbidden.
There are a number of legends associated with Naga pancahmi. One has it that on this day, while tilling his land, a farmer accidentally killed some young serpents. The mother of these serpents took revenge by biting and killing the farmer and his family, except one daughter, who happened to be praying to the Nagas. This act of devotion resulted in the revival of the farmer and the rest of his family. Since then, Nag Panchami has been celebrated in India. It is believed that in reward for worship, snakes will never bite any member of the family.
There is yet another legend related to the festival. It goes that young Lord Krishna was playing with the other cowboys near river Yamuna, when the ball got entangled in the high branch of a tree. Krishna volunteered to climb the tree and fetch the ball. Below the tree, a terrible snake Kaliya used to live in the river. Suddenly Krishna fell from the tree into the water. The terrible snake came up with anger, but Krishna started jumping on its head. Finally, Kaliya said sorry to Lord Krishna and He forgave the snake and let it go free. Since then, on Nag Panchami day, the victory of Krishna over the Kaliya snake is commemorated.
In India, snakes are so revered that temples have also been erected in their honor. There is a particularly famous one in Mysore, at a place called Subramania (Sheshnaga). The Naga culture was fairly widespread in India before the Aryan invasion, and continues to be an important segment of worship in certain areas. After the invasion, the Indo-Aryans incorporated the worship of snakes into Hinduism. The thousand-headed Ananta is Vishnu's couch and also holds up the earth, while snakes play an ornamental role in the case of Shiva. Naga panchami is another form of honoring the snakes.