Did you know that Lord Vishnu had a five headed snake? Snakes are considered holy by Hindus. They are worshipped during festivals like Nag Panchami and worshipped via the Snake-goddess Manasa. Sheshnag is the ‘Nagaraja’ or the King of the snakes and also took part in the story of creation with Lord Vishnu. In the Puranas Sheshnag is believed to hold all the planets of the Universe on his vast hoods. A devotee of Lord Vishnu, he constantly sings the glories of his Lord from all his mouths.
According to the Mahabharta, Shesha was born to Rishi Kashyapa and his wife Kadru. Kadru gave birth to a thousand snakes, of which Shesha was the eldest. After him came, Vasuki, Airavata and Takshaka. Many of Shesha's brothers were cruel by nature and took great pleasure in harming people.
Appalled with the terrible behaviour of his brothers, Sheshnag left his family and decided to seek forgiveness and also take on a penance. He lived merely on air and meditated in a number of places, including Gandhamadana, Badrikashrama, Pushkara, Gokarna and the Himalayas.
Pleased with his dedication and devotion, Brahma appeared before Sheshnag and told him to ask for a blessing. Sheshnag requested that he should be able to keep his mind under control, so that he could continue with the discipline in his practices. Brahma gladly bestowed the blessing upon him.
Brahma then asked a favour of Shesha - to go beneath Earth and stabilise it. Sheshnag was only too happy to be given this responsibility. He immediately went to Patala (the Netherworld), raised his hood and balanced the Earth over it. It is believed that he supports the Earth even today. (Ref: Dolls of India)
Lord Vishnu is always seen with Sheshnag in images. This mystical 5 headed-snake stands with its fangs open over the head of Lord Vishnu. The coiled body of the snake forms the throne on which Lord Vishnu is reclining. This snake is worshipped by Hindus as it is the seat of Lord Vishnu.
Krishna, Lord Vishnu’s avatar was born to Devika and Vasudeva on a very stormy night.
When Vasudeva was carrying baby Krishna across the river to Gokul to protect him from evil Kans. The Sheshnag rose from the river and shaded the father and child like an umbrella.
Both the Devas (Gods) and Asuras (Demons) wanted ‘Amrit’ (elixir or eternal life), but to get it, they had to churn the great seas of the world, Samudra Manthan. The Sheshnag had then become the rope with which the seas were churned.
According to Hindu mythology, he had descended to Earth in two human forms, Lakshmana (Lord Rama's brother) and Balarama (Lord Krishna's brother).