Shark
Bhagavad-gita As It Is
BG Chapters 7 - 12
BG 10.31, Translation and Purport:
Of purifiers I am the wind, of the wielders of weapons I am Rāma, of fishes I am the shark, and of flowing rivers I am the Ganges.
Of all the aquatics the shark is one of the biggest and is certainly the most dangerous to man. Thus the shark represents Kṛṣṇa.