The Nagas and their wives Naginis are strange magical serpents often with human heads, and can, if they so choose, take on wholly human form.

The word Naga is a Sanskrit word and means snake and especially the cobra, which is a specific type of hooded snake. In Indian mythology Nagas are serpent beings under the sea. They, are human from the waist up and cobra from the waist down, and they have slate-colored skin. All Nagas are considered the offspring of the Rishi or sage Kasyapa the son of Marichi . Sage Kasyapa had two wives, Kadru and Vinata. While Kadru desired many offspring Vinata desired few but powerful offspring. Kadru laid thousand eggs which hatched into snakes, and Vinata laid two, which hatched into the charioteer of Surya the sun god and Garuda.As a result of a foolish bet, Vinata became enslaved to Kadru and her son had to work for the snakes as a slave. When Garuda asked the snakes what he would have to do in order to be released from his bondage, they told him he would have to bring them "amrita" the elixir of immortality. Garuda stole the elixir from the gods and brought it to the serpents in fulfillment of their requirement, but prevented them from consuming it and achieving immortality. From that point onward, the arch-rivals of the Nagas became the gigantic bird-man Garuda .

In the great epic Mahabharata ,Nagas are shown as creatures with negative character. They are also portrayed as the deserving victims of the snake sacrifice as described in the scriptures, the Puranas and of predation by the rapacious birdman Garuda. The Mahabharata describes them as "persecutors of all creatures", and tells us "the snakes were of virulent poison, great prowess and excess of strength, and ever bent on biting other creatures" The epic also describes Nagas having a mixture of human and serpent like trait.

There are many stories involving the Nagas and they occupy an important place in the contemporary cultural traditions of Hindu religion .In India, nagas are considered nature spirits and the protectors of springs, wells and rivers. They bring rain, and thus fertility, but are also thought to bring disasters such as floods and drought. In South India they are believed to be associated with fertility and prosperity and expensive grand rituals like Nagamandala are performed in their honour .The Nagavanshi of North India consider them as a descendants of Nagas. Among the prominent nagas of Hinduism are Manasa,Shesha or Sesa and Vasuki.Vasuki is regarded as the King of the Nagas who helped the devas recover amrita from the Ocean of Milk.The worship of the nagas is believed to have emerged from the aboriginal inhabitants of the Ganges valley .It had its beginning in the non-Aryan circles because the Vedic literature has nothing much to say about the nagas .Vrtra is conceived as a monstrous serpent and in classical mythology he was replaced by Sesa, the mighty seven-headed cobra on whose coils Visnu sleeps during the cosmic night-a wholly benevolent divinity, representing endless time. According to both ancient and more recent belief, Nagas may be dangerous, but if treated with respect and won over with offerings of milk they might bring fortune and success for their patrons. Even today the real snake is also worshipped mainly in the country districts, at a special festival in the rainy season.

In Buddhist literature naga generally has the form of a large cobra-like snake, usually with a single head but sometimes with many. In Buddhist painting, the naga is sometimes portrayed as a human being with a snake or dragon extending over his head.