17) VAMAN AVATAR (Incarnation as a Dwarf) : Lord Vishnu took his seventeenth incarnation as a Dwarf, when Bali the king of the demons had captured the entire three worlds. Indra and all the other deities were wandering all around after losing the heaven.
To help the deities regain control over the heaven. Lord Vishnu disguised as a dwarf went to Bali when he was busy performing a 'Yagya' and demanded earth measured by his three steps. When 'Bali' agreed, he transformed his form from a small dwarf to a giant. Consequently he covered all the three world with his two steps. Ultimately he regained heaven for the deities.