Hindus believe that Vishnu had many important Avatars, and the Varaha avatar was the third avatar of Vishnu. In this avatar, Vishnu took the form of a black varaha. Varaha is a Sanskrit language word that means a boar. The Hindu scriptures tell a story about this avatar. There was a daitya (a demon) named Hiranyaksha. He threw the Earth (called Prithivi by the Hindus) into the waters of the ocean. The earth was about to sink in the ocean. At this point, Vishnu took the form of a black boar. He entered the water and carried the earth on its body and brought the earth safely to where it should be. Thus, Vishnu as a varaha saved the earth from being destroyed.
|Wikimedia Commons has media related to Varaha.|