Cybershades were a variant of Cybermen that served Miss Hartigan and the Cybus Cybermen
Biology and Appearance
Cybershades were wraith like creatures with bronze Cyber-heads.The doctor remarked that cybershades may have the brains of cats or dogs. They were seemingly unable to run upright, instead they wre only known to run on all fours. They were incabable of speech, instead making growls to communicate with others.. It was comfirmed by the Doctor Who Website that the Cybershades have animal brains in the Jack Harness Monster file!
Instead of the traditional handle-bars, Cybershades had handle-bars that resembled piping that was connected to their heads, instead of the normal handle-bars that went into a crest on the top of a Cyberman's head. (DW: The Next Doctor)
Despite this, a Cybershade was seen using a horse and cart.
History
Sometime during the 19th Century, the Cybermen of a Parralel Earth broke out of The Void. Needing extra work force, they created the Cybershades as guards and scouts, modelling them on animals so as not to draw to much attention. At least 16 Cybershades were created.
Despite this, Cybershades had been sighted Before the Cybermen had come through the Void. The most likely explanation ist that the Cybershades were somehow created in the Void, or that they had just been sighted before the Cybermen. Perhaps they were "Pilot Fish"?
When the Cybermen made contact with Miss Hartigan, the Cybershades were placed under her command. At least one Cybershade was being hunted by "The Doctor"., but it always managed to evade him.
When Miss Hartigan (now the Cyber-King) took control of a the Cybermen and entered a large, mobile Cyber factory, at least two Cybershades accompanied her (although there could have been more). When The Doctor gave her back her emotions, the Cybershades exploded along with her and the Cybermen, presumably making the Cybershades extinct.
Behind the scenes
Cybershades were first revealed in Russell T. Davies: The Writer's Tale, where it was revealed that they would appear in The Next Doctor.
In the episode at least one Cyberahade was played by Ruari Mears, who had played the part of Hath Gable in The Doctor's Daughter.