Hecate

You may be looking for the spaceship of the same name.

Hecate was a goddess worshipped by a murderous coven of witches in Moreton Harwood. The coven, who had intended to use Brendan Richards as a human sacrifice, was defeated by Sarah Jane Smith and K9 in December 1981. The members of the coven were later charged with attempted murder. (TV: A Girl's Best Friend) Once, about to mention something to do with Hecate to Sally and Evelyn Smythe, the Sixth Doctor thought better of it, admitting that he was “not sure if that was canonical”. (AUDIO: Doctor Who and the Pirates)