Robot servants of the Dominators, and roughly the size of a box just large enough a BBC intern could fit into and move around in, the Quarks acted both as guard-bots and drillers. Their job was to dig a big hole in the planet so that the Dominators could use up the core’s energy, or to slowly amble after you making a chorus of squeaks beeps and boops and sometimes shooting at you

The Quarks and their D0minator masters have been featured in many Doctor Who novels, comics, and audios, but were seen on TV in the episode The Dominators and The War Games.