Which avatar of Vishnu is a dwarf?

Vamana is the dwarf avatar of Vishnu.

Vamana is traditionally counted as Vishnu’s fifth avatar and one of the Dashavatara, the ten principal incarnations celebrated in many Hindu traditions. The Sanskrit name Vamana means “dwarf” or “short in stature,” matching the form Vishnu assumes in the best-known version of the story.

Vamana appears before Mahabali, a powerful and generous daitya king, during a sacrificial ceremony. He asks only for as much land as he can cover in three steps. After Bali agrees, Vamana expands into the cosmic form called Trivikrama. His first two strides span the earth and heavens; when no place remains for the third, Bali offers his own head.

The story is not simply a tale of defeat. Bali is generally portrayed as noble and devoted, and Vishnu rewards his integrity by allowing him to rule the netherworld. Vamana is also strongly associated with Onam in Kerala, a festival linked to Bali’s annual return.