SB 10.11.48

sa vai bako nāma mahān
 asuro baka-rūpa-dhṛk
āgatya sahasā kṛṣṇaṁ
 tīkṣṇa-tuṇḍo ’grasad balī
Synonyms: 
saḥ — that creature; vai — indeed; bakaḥ nāma — by the name Bakāsura; mahān asuraḥ — a great, gigantic demon; baka-rūpa-dhṛk — assumed the bodily shape of a big duck; āgatya — coming there; sahasā — all of a sudden; kṛṣṇam — Kṛṣṇa; tīkṣṇa-tuṇḍaḥ — sharp beak; agrasat — swallowed; balī — very powerful.
Translation: 
That great-bodied demon was named Bakāsura. He had assumed the body of a duck with a very sharp beak. Having come there, he immediately swallowed Kṛṣṇa.