Gears: a set of toothed wheels that work together to alter the relation between the speed of a driving mechanism (such as the engine) and the speed of the driven parts (the wheels).
What if those "wheels" were shaped like squares? Or ovals? Or fish? Clayton Boyle is an engineer of seemingly impossible, organically-shaped gears. Watch Boyle demonstrate his creations below; scroll down for a tutorial on making your own.