Mechanoid

Mechanoids were large, spherical robots originally created to serve humans. Some of them had been sent to prepare the planet Mechanus for human colonization, but Earth got caught up in an interplanetary war and the colonists never arrived. Steven Taylor crashlanded on Mechanus and was taken prisoner by the Mechanoids. The Daleks followed the Doctor's TARDIS to Mechanus and battled the Mechanoids. (The Chase)

Davros once combined organic tissue with Mechanoid shells to create Juggernauts. (The Juggernauts)