Tussan

As related in Postar's Scrolls, Tussan was the last Council Leader of the Arcalian Gallifreyan Council of ancient Gallifrey. As was tradition, he had a talking cat as an advisor.

Tussan was presiding when the Council had to rule over whether to fund Rassilon and Omega's experiments with black holes. Intent on belittling the two Prydonians and putting them in their place, Tussan delegated the decision to his cat, only for the cat to unexpectedly authorise the experiments. After the experiment's success, he later tried to put the increasingly influential Rassilon into forced retirement, but Rassilon instead overthrew him and the Arcalian Council, becoming the first official President of the High Council of the new societal order of Time Lords he instituted. (PROSE: The Legacy of Gallifrey)