Control node (The Girl in the Fireplace)

Clockwork Man was the leader of the Clockwork Droids operating on the SS Madame de Pompadour. The Tenth Doctor liked this particular droid, saying it was his favourite, because it was "Mr Thick Thickity Thickface from Thicktown, Thickania," and promptly poured Anti-Oil into its head. (TV: The Girl in the Fireplace)