Beavis

Dr. Beavis was a medical specialist called in from London by Ashbridge Cottage Hospital to take a look at the Third Doctor. He enlisted Corporal Forbes to guard his car, and seemed very doubtful of Henderson's claims that the Doctor had an alien physiology. Before he could examine the Doctor, he (the Doctor) stole Beavis' clothing and car when he escaped from the hospital, though both were eventually returned. (DW: Spearhead from Space)