Lamia

Madame Lamia was Count Grendel's surgeon and engineer.

Biography
Lamia constructed the androids that Grendel used in his plots to kill Prince Reynart and the Fourth Doctor. Although she was a commoner, she and Grendel had a romantic relationship of some kind, although she herself acknowledged that he was not as devoted to her as she was to him.

After an android of Romana I failed to kill the Doctor at the Pavilion of the Summer Winds, she ran out of the building, but was accidentally shot and killed by one of Grendel's men. (TV: The Androids of Tara)