The video: The awkward march of the military's Robo-mule was sturdy, if inelegant. Now, the newest animal-inspired robot sponsored by the Pentagon's Defense Advanced Research Projects Agency (DARPA) takes its cues from a much faster beast: The cheetah. Built by robotics firm Boston Dynamics, robo-cheetah just set a new speed record for multi-legged robots, clocking in at 18 miles per hour. (Watch a video below.) The machine's cat-like spine actually flexes and extends to maximize the robot's stride, and the galloping machine is "constantly tipping forward, falling and regaining equilibrium with every step" — just like real animals. Soon, robo-cheetah will be "running much faster and outdoors," says Boston Dynamics' Alfred Rizzi. "We really want to understand the limits of what is possible for fast-moving robots."

The reaction: Robo-cheetah is "freakily fast," says Katie Drummond at Wired. Consider human world-record holder Usain Bolt, "who clocked an amazing 28 mph during the 100-meter sprint in 2009." Robo-cheetah is right on his heels, and may surpass Bolt soon. At this rate, says Andy Greenberg at Forbes, such robots may one day "leave flesh-and-blood animals in the dust, too." Take a look: