sa vai bako nama mahan
agatya sahasa krsnam
tiksna-tundo ’grasad bali
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
That great-bodied demon was named Bakasura. He had assumed the body of a duck with a very sharp beak. Having come there, he immediately swallowed Krsna.