It probably would have proven too impractical because the makeup appliances were so delicate as to be single use only, but I would love for the Doctor to wind up with a CatKind traveling companion.

This is what I envision in my mind's eye. (Sorry, but I had to depict my favorite Doctor.) Ever more impossible because the team had to restrict the felinoid appearance to just the face (hence the head to toe "nun" attire and Brannigan clothed to resemble a WWI flying ace complete with a flight cap and scarf.
But one can daydream.