Kadru

According to the Adi Parva of the Mahabharata, Kadru (Kadrū) is said to be the daughter of Daksha. Kashyapa married Kadru and twelve of Daksha's other daughters. Kadru was the mother of a thousand Nagas. 

Legends of Kadru tell of her relationship with her elder sister Vinata, who was also one of Kashyapa's wives. As the story in Mahabharata goes, 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 Nagas, 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. 

In another tale in Brahma Purana, 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.