A device for driving piles into the ground. The contemporary pile driver consists of a steel frame that supports the undriven pile, perched atop of which is a heavy weight that slides up and down in a track. This weight is raised up and fired down pneumatically. The weight strikes the top of the pile, smacking it down a dozen more inches into the sand or mud.
This process is neat to watch, but only for a short while as it becomes monotonous. Surprises are few and far between in the pile driving field. It is also noisy.
Often, in Warner Brothers' cartoons, Tweety would dispatch Sylvester by pile driver. Or rather, Sylvester would do the honors himself, through lack of foresight or situational awareness.
Consider your surroundings and design for the unexpected!