Althrace brain
From Tardis Wiki, the free Doctor Who reference
Giant living brains were used as machines by the Lords of Althrace, being part of the bio-mechanical symbiosis of Althrace. The brains had legs and were hooked up by various wires to the crystal towers in which they lived. The "face" of a brain was a giant circular screen which could be used to display the files of the Althrace, showing footage of universal history.
Dakon Theka and Thane of Kordar took the Fifth Doctor to a brain to show him the origins of Melanicus. (COMIC: The Tides of Time [+]Loading...["The Tides of Time (comic story)"])