Clawrantular

The Clawrantulars were an arachnid-like species which were enslaved at some point by the Daleks. It is unlikely these creatures were sentinent enough to have obeyed the Daleks by choice, as they failed in finding the seven crystals of Karn which would enable their Dalek masters to control all life in the universe. (SP: Doctor Who and the Daleks in The Seven Keys to Doomsday)