Scorpionfish or Stonefish?
Both look like stones or corals and are very well camouflaged. The stonefish (left) has a short and wide upturned mouth on a flattened face which gives it a distinct grumpy appearance. Its eyes are set deeper into the head. From the top, it looks more rounded with the head and torso looking top-heavy and a tail that is often curled slightly to one side. The scorpionfish (right) looks more like a fish with a slender body, longer snout and a mouth that is angled but not grumpy.