Shark - lever

The jaws of this shark are put in motion by a trigger at the bottom of the stick (there's a rope inside which transmits this motion). The trigger is pretty long, but the shark's teeth close strongly, especially the incisor teeth.

This is how a lever works, allowing us to work by applying less force.

If we want to move the glass-wipers all over the car windscreen, we just have to move a short lever on the other extremity, but a pretty powerful engine has to do it.