Mechanical lobster?

Is this a box of dental instruments maybe, or some form of torture, or a mechanical lobster plus other bits and pieces?
Nothing as interesting I'm afraid. It is a box of 15 feet, which arrived today, and they are for my sewing machine. I actually only needed the one bad beefy lobster boy in the centre, but it wasn't much more expensive to buy all 15 than it was to just purchase the one. 
And of course - they're made in Taiwan. How come, when we've visited Taiwan, (which we have done many times, to visit our son and his family) we never see things like this for sale?
The one in the centre by the way is called a "walking foot".