Professor Watkins was a scientist and the uncle of Isobel Watkins. After inventing the Cerebration Mentor, he was kidnapped by Tobias Vaughn, who forced him to develop it for use as a weapon against the Cybermen. Watkins was later rescued by UNIT.
Watkins was at least an acquaintance of Edward Travers and his daughter. From them, he learned much about the Second Doctor and the TARDIS. When he finally met the Doctor, his foreknowledge caught the Time Lord by surprise. (TV: The Invasion)