This is one of the most amazing, beautiful things I've ever seen. Theo Jansen is a Dutch kinetic artist. He creates mobile autonomous "animals" made from plastic tubing and water bottles. These creations are able to walk via a simple mechanism that is kind of an extension of a wheel. They are powered by wind energy that they are able to store. They can act in self-preservation via a simple "brain" that keeps them away from water and other dangers. Here is a talk he did for TED:
and here is his website:
This is absolutely brilliant!
Here's a simulation of Jansen's reengineering of the wheel that makes this locomotion possible.