Varaha, the boar, is third in the Dashavatara, the ten avatars of Lord Vishnu. Varaha is the symbol of the restoration of the earth and the establishment of a new age. In the Vishnu Purana, Varaha is represented as the eternal upholder of earth. He is known as the picture of the Supreme Being who brings order amidst chaos in the world.
According to the oldest of the Puranic scriptures, the legend is as follows:
The gate-keepers of Vishnu's dwelling Vaikuntha, Jaya and Vijaya were cursed by the four Kumaras to be born as demons. They were then born on earth as Hiranyaksha and Hiranyakashipu to Kashyapa and his wife Diti. They were one of the races of demons called Daityas. The two demon brothers were pure evil and created mayhem all across.
The elder brother Hiranyaksha practised austerities and as a consequence was blessed by Brahma with a boon that made him indestructible by any animal or human. He was engaged in war with the gods. He took the earth in the depths of primitive waters. In some versions, the earth gives a cry of agony; in others, she takes the form of a cow and requests Lord Vishnu for rescue from the hands of the demon. In his boon, Hiranyaksha had not included the boar in the list of animals that could kill him. Therefore, Lord Vishnu incarnates into Varaha, a boar, with huge tusks and goes down to the ocean.
Varaha challenges Hiranyaksha for a battle. The demon ridicules Varaha and obstructs him to rescue earth. Varaha lifts the earth on his tusks, when provoked and slays the demon after a thousand-year battle. Afterwards, Varaha rises from the ocean with the earth in his tusks and places her gently above it in her original position.