Venomous Aquatic Animal, Camouflaged as a Rock

Puzzle 2 of Predators Hard Pack

Question is: Venomous Aquatic Animal, Camouflaged as a Rock

and the answer is: STONEFISH

Word Meaning:

STONEFISH — A venomous tropical marine fish resembling a piece of rock, of the genus Synanceia, found in the Indian Ocean and Pacific Ocean

Definitions from Wiktionary.