Barnabus

Barnabus was a robot invented by the Second Doctor to do chores around the TARDIS — serving tea, for example — and could also operate the Time/Space craft. While on an unnamed planet, Barnabus saved the Doctor, John and Gillian from a gun crew who mistook them for invaders. (COMIC: Barnabus)


 * Strangely, Barnabus was never seen nor referred to again afterwards.