Skaro Degradations

The Skaro Degradations were Dalek force part of the Last Great Time War. The Degradations were created by the Daleks during experiments to retro-evolve the Dalek genome. The results created abominations of the Dalek form. The Daleks put the Degradations to use against the Time Lords. The War Doctor encountered the Degradations on Moldox. (PROSE: Engines of War)

They were described by the Tenth Doctor as one of the potential horrors that would be released when broke the time-lock on the war, along with the Nightmare Child, the Horde of Travesties, and the Army of Meanwhiles and Neverweres led by the Could've Been King. (TV: The End of Time)