Creepy.

"This video shows a demonstration of the "Cheetah" robot galloping at
speeds of up to 18 miles per hour (mph), setting a new land speed record
for legged robots. The previous record was 13.1 mph, set in 1989.

The robot's movements are patterned after those of fast-running animals in
nature. The robot increases its stride and running speed by flexing and
un-flexing its back on each step, much as an actual cheetah does.

The current version of the Cheetah robot runs on a laboratory treadmill
where it is powered by an off-board hydraulic pump, and uses a boom-like
device to keep it running in the center of the treadmill. Testing of a
free-running prototype is planned for later this year.

While the M3 program conducts basic research and is not focused on specific
military missions, the technology it aims to develop could have a wide
range of potential military applications."