In Hindu mythology, according to the Adi Parva of the Mahabharata, Kadru is usually regarded as the daughter of Daksha. Kashyapa married Kadru and the other eleven daughters of Daksha. Kashyapa was the son of Marichi, who was the manasputra or mind-born (spiritual) son of Brahma. Kadru was the mother of a thousand nāgas. She is also said to be descended from Vishnu.
Legends of Kadru tell of her relationship with her elder sister Vinata, who was also one of Kashyapa's many wives. In one story, Kadru and Vinata vie to bear children of Kashyapa who are more powerful than each other's children. While Kadru gives birth to a thousand nāgas, Vinata has two sons, Aruṇa and Garuda. Kadru is also portrayed as more scheming and wily than Vinata. She challenges Vinata to guess the colour of the tail of Uchchaihshravas, the divine white horse. After Vinata says the tail is white, Kadru tricks Vinata by directing her sons to coil around the horse's tail, causing it to appear black. As a result, Vinata loses the bet and she and her sons must become the slaves of Kadru and her sons. Another legend states that when Kadru asks Garuda to take her sons on his back to the abode of the sun so they can pay obeisance and they are scorched, Vinata asks Garuda to carry water of the Ganges from the nether world and sprinkle it on the nāgas to revive them.
In another tale, Kadru and Suparna, another of Kashyapa's wives, disobey Kashyapa and disrupt some sages who are performing rites on the banks of the Ganga. As a result, they are turned into rivers. Kashyapa is only able to restore them to their original forms by performing penance to Shiva.