The Cybershades are part animal and part cyberman.
The Cybershades are basically the Cybermen's pets who hunt around the streets of London. There were about 16 Cybershades apparently. When the Doctor first met one he was with Jackson Lake who thought he was the Doctor. The Cybershade took both men up into a building and then jumped off of the edge. Luckily Rosita cut the rope and saved Jackson Lake and the Doctor's lives. When Miss Hartigan was at the graveyard the Cybershades arrived with the Cybermen to kill off everybody apart from four people. The Cybershades would chase the men and take them to the Cybermen to be killed.
When the four humans were wearing cyberhead sets they were taking the children under London to help make the Cyberking rise. The Cybershades would be on guard when the children were being taken.
The Cybershades later on would follow the remain Cybermen into the Cyberking to protect Miss Hartigan who was the new Cyberking. There were only two inside the Cyberking. The Doctor did get into the Tardis which was Jackson Lake's balloon and would destroy the Cyberking, the Cybermen, Miss Hartigan and the Cybershades.
The Cybershades appeared in:
2008 Christmas Special: The Next Doctor