Baggolt

The Baggolts were the robot servants of the Ethereals. They rebelled against their masters and tried to vaporise them, but only succeeding in turning them into living clouds. Five eketrons later, the First Doctor visited their world, restored the Ethereals' original bodies, and helped their leader, Mitzog, put an end to the Baggolt rebellion. (PROSE: The Cloud Exiles)

The Baggolts were among the aliens stuck on Denossus when it was transported to the Time Vortex by the Vortexians. They would remain trapped for over twenty years until the Vortexians were expelled by the Second Doctor. (COMIC: Land of the Blind)