In Hindu tradition Shesha; also known as Sheshanaga; is the king of all Nagas; and of all serpent deities; one of the primal beings of creation; and according to the Bhagavata Purana; an avatar of the Supreme God known as Narayana. He is also known as Balarama and Sankarshana.

In the Puranas; Sheshanaga is said to hold all the planets of the Universe on his hoods and to constantly sing the glories of Vishnu from all his mouths. He is sometimes referred to as Ananta Shesha which translates as endless-Shesha or as Adishesha which means the first Shesha.

It is said that when Adishesa uncoils; time moves forward and creation takes place. When he coils back; the universe ceases to exist. 'Shesha' in sanskrit texts; especially those relating to mathematical calculation; also implies the 'remainder' - that which remains when all else ceases to exist.