Oh, hey! That's my bot. :-) Tapster is usually powered by Arduino, but I modified it to run on Raspberry Pi for PyCon this year.

The source files (3d printable files and code) are on GitHub. https://github.com/hugs/tapsterbot When I'm in-stock, you can pick one up here: https://www.tindie.com/products/hugs/robot-that-plays-angry-...