Narasimha Avatar

Lord Vishnu took his fifteenth incarnation as Nrisimha, having upper portion of his body in the form of lion and the lower portion resembling of a man. In this incarnation he protected Prahlada from his father Hiranyakashipu the demon. He killed Hiranyakashipu by tearing his body apart by his nails. Lord Vishnu had to attain this form because Lord Brahma had blessed Hiranyakashipu, that a Human being could not kill him.