Shesha is a naga who is primal snake (naga) of creation. Shesha is closely associated with Vishnu; means that which remains, from the Sanskrit root shi?, because when the world is destroyed at the end of the kalpa, Shesha remains. Balarama, Lakshmana, and Nityananda Prabhu, are considered avataras of Shesha (or vice versa). Patañjali is also considered an emanation or incarnation of Shesha and is iconographically depicted in naga form with naga canopy. http://en.wikipedia.org/wiki/Shesha