A robotic dog developed by engineering company Boston Dynamics for the American military has become an Internet star.
Video footage of BigDog, which has been built to carry equipment and march alongside troops in rough terrain, was viewed by more than 6 million people on YouTube.
The robot is the size of a large dog and is powered by a gasoline engine that drives its hydraulic system, reports The Daily Mail.
It runs at 4 mph and can climb slopes up to 35 degrees steep and walk across rubble while carrying a 340lb load.
During a demonstration video, the intrepid hound managed to keep its footing on an uneven surface after being shoved sideways.
A computerised brain sits at its core, and controls a small petrol engine, which drives its aluminium legs.
Each of the legs features three joints that can be repositioned 500 times every second, meaning the robot can even withstand a hefty blow to its body.
Current models of BigDog are remote-controlled from army bases by commanders.
However it is thought that future versions will be built with eye-like sensors that allow it to become 'unleashed' by making intelligent decisions about a journey.