Cyberdrone

Cyberdrones were disembodied Cyber-heads which served as an advance guard for the Cybermen during the Cyber-Wars.

Characteristics
Capable of flight, Cyberdrones appeared as disembodied Cyber-helmets corresponding with the Cybermen associated with the Cyber Legions in N-Space, who themselves were all but identical to those created by Cybus Industries in Pete's World. Their eye-pods, which gave a blue glow of light, served as both a means of vision, providing a heads-up-display to pinpoint targets, and an energy weapon, firing blue pulses. (TV: Ascension of the Cybermen)

History
In the immediate aftermath of the Cyber-Wars, the Lone Cyberman and his Cyberguards used a flight of Cyberdrones to attack the last surviving humans. (TV: Ascension of the Cybermen)

Other references
In one parallel universe, a Cyber-Controller used "Cyberdrone" as a term for the fully-converted Cyberman units subordinate to it. (AUDIO: Code Silver) Similarily, a Borg-modified Cyber-Controller who crossed from N-Space to the Federation universe refered to its subordinates as "drones". (COMIC: Assimilation²)

Behind the scenes

 * In the documentary Upgrading the Cybermen, their name is spelled "Cyber Drone".