BigDog

A fascinating video, but you might not want to watch it just before bedtime.

Via The Bad Astronomer, who commented:

….it’s definitely quadrupedal and incredibly life-like in its reaction to such things as a broad kick, a hill, and a slippery surface.

And that buzzing noise! If they want to terrorize a small town, they should paste fly wings on it and let it loose. Pitchforks and torches would follow quickly.