After the Cybermen had been pulled into the Void following the Battle of Canary Wharf in 2007, a small number of them were able to escape the Void and land in 19th-century London, where they went about planning their conquest of Earth. With few resources available to them, the Cybermen created a new breed of slaves called Cybershades: strange creatures with bodies covered in thick black fur with bronze Cyberman faceplates. The Cybershades were created by harvesting animal brains rather than human brains, and so they behaved in a very feral manner, unable to speak and only able to move on all fours. They were extremely agile and were capable of leaping great heights and climbing walls.
All of the Cybershades self-destructed when the Doctor destroyed the Cyber-King, eliminating the Cybermen's presence in the 19th century.