VAMANA AVATAR

Vamana (Devanagari: वामन, IAST: Vāmana, lit. dwarf) is described in the Puranas as the fifth avatar of Vishnu, and the first incarnation of the Second Age 
orTreta yuga.^[1] He is the first avatar to appear as a human, although he does appear as The Bhagavata Purana describes that Vishnu descended as the Vamana avatar to restore the authority of Indra over the heavens, as it had been taken byMahabali, a benevolent Asura King. Bali was the great grandson of Hiranyakshipu, the grand son of Prahlada and son of Virochana.

Vamana, in the guise of a short Brahmin carrying a wooden umbrella, went to the king to request three paces of land. Mahabali consented, against the warning of his guru, Sukracharya. Vamana then revealed his identity and enlarged to gigantic proportions to stride over the three worlds. He stepped from heaven to earth with the first step, from earth to the netherworld with the second. King Mahabali, unable to fulfill his promise, offered his head for the third.

Vamana then placed his foot and gave the king immortality for his humility.^[3] He was also allowed to return every year to see the citizens of his country. The festival of Onam for some and first day of [Diwali] for some is related to this return of Mahabali.

Mahabali is seen as a symbol of prosperity and love. In worshiping Mahabali and his ancestor Prahláda, he conceded sovereignty of Pátála, the netherworld. Some texts also report that Vamana did not step into the netherworld, and instead gave its rule to Bali. In giant form, Vamana is known as Trivikrama.^[4]a dwarf Brahmin.

                          Source: wikipedia