Scorpion Fish - Thailand The scorpion fish, one of the most venomous in the world, uses camouflage, and the ability to remain completely motionless, to snap up small unsuspecting fish. For a diver, they look like the rest of the coral, and many have reached out and placed their hands right onto them - another good reason never to touch anything on the reef. Semi-hidden spines in the dorsal fin are coated with a venomous mucous, and they slide right in to human flesh, creating what has been documented as days and weeks of searing pain.