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.