Harry Sullivan (Doctor Who)
Harry is a doctor in the Royal Navy, who is also a medical officer to the United Nations Intelligence Taskforce, the military organisation to which the Doctor works for as a scientific advisor. He is first mentioned (though not seen) in Planet of the Spiders, when the Brigadier thinks the Third Doctor has gone into a coma. The Brigadier calls "Doctor Sullivan" and asks him to come to the Doctor's laboratory, but tells him not to bother when Sergeant Benton wakes the Doctor by offering him a cup of coffee. In the next serial, Robot, after the Doctor's third regeneration, Sullivan is called in to help him, and ends up travelling aboard the TARDIS with the Fourth Doctor and Sarah-Jane Smith (played by Elisabeth Sladen) for several adventures.