Scorpion fish

The Scorpaenidae are a family of mostly marine fish that includes many of the world's most venomous species. As their name suggests, scorpionfish have a type of "sting" in the form of sharp spines coated with venomous mucus. The family is a large one, with hundreds of members. They are widespread in tropical and temperate seas but mostly found in the Indo-Pacific. They should not be confused with the cabezones, of the genus Scorpaenichthys, which belong to a separate, though related, family, Cottidae. Scorpaenidae was described as a family in 1826 by the French naturalist Antoine Risso. The family is included in the suborder Scorpaenoidei of the order Scorpaeniformes in the 5th Edition of Fishes of the World but other authorities place it in the Perciformes either in the suborder Scorpaenoidei or the superfamily Scorpaenoidea. The subfamilies of this family are treated as valid families by some authorities.

Source: Wikipedia