Google has acquired the engineering company that developed Cheetah, the world's fastest-running robot and other animal-based mobile research machines.
Boston Dynamics, which contracts for the US military, is the eighth robotics company snapped up by Google this year.
Both the price and size of the project, which is led by former Android boss Andy Rubin, are being kept under wraps.
However, analysts say the purchases signal a rising interest in robotics use by consumer internet companies.
Online shopping portal Amazon, for example, recently announced plans to deploy a fleet of delivery drones.