From the Cabaret Mechanical Theatre shop site:
An ingenious new piece from the Fourteen Balls Toy Company. Three skeleton cyclists are being chased by a dog. In turn they turn their heads to see if he is still in pursuit, tongue wagging! Matt Smith's new exhibit design has a tremendous sequence and meticulous workmanship. An exquisite collectors piece,
Here's where you can see more pictures of The Boneshakers automaton.