Also known as Adishesha. From Brahma were formed the prajapatis and one of them was Anantha, according to Ramayana Aranyakanda Sarga 14 verse 7. According to Mahabharata Adiparva Chapter 105 verse 41, Anantha was born to prajapati Kashyapa and his wife Kadru. Also, as per Mahabharata Adiparva Chapter 67 verse 152, Krishna’s brother Balarama was an avatar of Anantha.
Vinata and Kadru were the two wives of Kashyapa. Vinata’s son was Garuda and Kadru’s children were Anantha, Vasuki, Thakshaka, Karkodaka and several other snakes. Once Vinata and Kadru had an argument over whether Airavata’s tail had black hairs. Vinata was certain there weren’t and Kadru was sure that there weren’t. They agreed that the one who lost the argument would have to be the other’s slave. Kadru called her sons that night and told them to latch on to Airavata’s tail and stay there so that she would win the argument. Several snakes agreed but the more prominent ones like Anantha were against this. Kadru cursed that the latter would burn in the sarpasatra that Janamejaya would hold. According to Mahabharata Adiparva Chapter 65, Anantha and the others were dejected and left the place.
Anantha left Kadru and meditated at Gandhamadana, Badaryashrama. Brahma appeared before Anantha and asked him to go to patala and hold the earth with his many heads, and that Garuda would help him. According to Mahabharata Adiparva Chapter 36 verse 24, Anantha was happy and immediately proceeded to patala.
As per Mahabharata Udyogaparva Chapter 110 verse 18, Anantha has a place in Varuna’s abode in the west
Anantha has been praised in the Vishnupurana. According to the scripture, a snake who is a manifestation of Vishnu lived in Patala and the demons were unable to even describe his prowess. He is worshiped by sages and devas and is called Anantha. He has a thousand heads and is easily identifiable by a prominent swastika. He lights up all the directions with the many jewels that adorn him, he strengthens the good forces and renders the asuras powerless. He is forever swaying as if in a trance, and wears a blue dress and many white jewels. He resembles another Kailash, holds a plough in one hand, a pestle in the other, and is served by two goddesses – Sri and Varuni. He wears the world as if it were a crown, and at the end of the universe’s life, Shiva appears as Rudra through Anantha’s face and consumes the worlds. Even the devas are unable to fully express his strength, stature or prowess. The jewels in his fangs makes it look as though he’s wearing a necklace. When he yawns, the world shakes. Gandharvas, apsaras, Kinnaras, Nagas, Charanas are all in awe of him, and can never see his ends. Hence is called Anantha (infinite) Raktachandana is applied on him by many nagas and his scent pervades all the directions. A sage called Yayagarga worshipped Anantha and learned the secrets of astrology. According to Vishnupurana Ansh 2 Chapter 5, such is the prowess of the snake who holds this earth and the skies above it.
The Devibhagavata describes Anantha’s home in patala. At the centre of patala, there is a place caled Anantha which is 30000 yojanas long. Here lives Anantha, also known as Sankharshana. He holds the world, the skies and Patala and when it is time for the destruction of the worlds, Sankharshana, a rudra emerges from within Anantha along with other rudras, equipped with weapons like the trident. Anantha is known to be handsome and radiant. Other snakes constantly prostrate before him and while they do so, they see their reflections in Anantha’s glittering fingernails, according to Devibhagavata Ashtamaskanda.