The Bio-Drone is a mobile heavy weapons platform used during the Second Alien War.
The Bio-Drone consists of an armored flying saucer-like chassis with an Ion Displacer engine, piloted by a brain housed in a sealed life tank. The Drone's propulsion system is similar to that of an Alien Sub, which enables it to glide through the water and provides limited flight capabilities during attacks on surface sites. It is armed with a powerful Auditory Disruptor, which is apparently an organic device based on the pilot brain's original vocal cords, meaning that the Bio-Drone's weapon literally screams targets to death.
In autopsy studies, it has been observed that the brains of many Bio-Drones possess numerous trauma scars, possibly due to mutilation prior to being fitted into the chassis. It would seem that the aliens butcher the brains into submission.
The Bio-Drone does have some drawbacks. When it moves, it leaves a trail of scorch marks and small fires behind it, making it relatively easy to track. Also, when the Drone has sustained heavy damage, the Ion Engine goes critical and explodes with stunning force. Despite these flaws, it is a very powerful heavy assault unit, ideal for large scale attacks against surface targets.