Narasimha is an avatar of Vishnu described in the Puranas, Upanishads and other ancient religious texts of Hinduism.
The legend on King Hiranyakashipu is one of the explanations Hindus look back to. The King condemned his son, Prahlad, from worshipping the god Vishnu. However, he continued to pray to him. Filled with anger, the King made a challenge to his son. He was to sit on a pyre along with his aunt Holika, believed to be unharmed by fire. The son accepted the challenge, praying to Vishnu to protect him. As the fire began, Holika was burnt to a crisp but Prahlad lived and was unharmed. This burning of Holika is the reason why Holi exists.