The stone with the big surprise is a fish that lives off the coast of Australia. It is called the stonefish.
The surprise is that the stonefish is the most poisonous fish in the world. Until very recently, to step on a stonefish meant death. But the Australian government has developed a special medicine for those unlucky enough to step on this monster.
It would be nice if the stonefish liked to lie alone on the ocean bottom, away from all other rocky looking things. But it doesn’t. It prefers to lie among stones so that it is well hidden.
When an unwary fish swims by, the stonefish gobbles it up with a quick movement of its mouth.
When stung by a stonefish, it is recommended to treat the area using heat and an anti-venom if necessary. Hot water above 45 degrees Celsius is known to destroy stonefish venom.