Boston Dynamics' latest iteration of BigDog, a battlefield robot being developed for DARPA (the folks who brung you the Internets). Look at it regain its balance after slipping on ice or taking a hefty shove. This thing is eerie.
Me, I'd make some kind of robotic pig's head for it before unleashing it against Al Qaeda, but that's just my juvenile sense of humor at work.
Warning: Video has sound -- some ungodly grinding, whirring noise that's even creepier than the robot.