K-9 is based on the robot dog in the sci-fi show, Doctor Who. However, my K-9 is a real, programmable, electronic robot (no radio control here, unless you count a wi-fi link to a laptop). He is made of metal (see photo of his skeleton for details), is powered by a 12 volt lawn tractor battery, has an Intel Celeron processor for a brain (basically a stripped-down laptop), and is propelled by two windshield wiper motors connected to lawn mower wheels. In the original design, he used an optical mouse interfaced with the floor via a spring-loaded tension system. The mouse sent detailed x/y position data to the computer. However, this waxed floor posed a problem for K-9, as the optics reflected at the wrong angles. I'm now moving to a traditional wheel encoder system. He uses servos to move his tail and head. His tail can go up and down, left and right. His head can do the same. Eventually, I'll hook up his ears to rotate via servo as well. He is mentioned in Linux Journal and an older version can be seen in action from the following news clip on YouTube.