The US military is set to take delivery of a new four-legged friend.

Big Dog is billed as the most advanced robot in the world by inventors Boston Dynamics.

A video of the hydraulic-powered beast has already had six million hits on YouTube.

Big Dog is designed to walk, run, climb on rough terrain and carry heavy battlefield supplies, all without falling over.

In trials, he reached a top speed of 4mph, climbed slopes up to 35 degrees and carried a 340lb load.

The US government is said to be keen to deploy a prototype by the end of the year.

For civilian fans, the creators are planning a scaled-down version, imaginatively called Little Dog.

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