Dare to touch the shark's teeth. Touch the wrong one and you get your finger bitten

An ingenious piece of nonsense to entertain any young child! Open the creature's jaws and press down on its teeth one at a time. Sooner or later you will find the tooth which will make the jaws snap shut frighteningly but quite harmlessly on your finger - unless you can get it out of the way in time, which is the plan. A different tooth trips the mechanism each time.