Jeremy Fitzoliver

Jeremy Fitzoliver was an upper-class photographer and occasional companion of the Third Doctor.

Biography
Fitzoliver was not popular at the Metropolitan magazine. Sarah Jane herself could barely stand him. He got the job mainly because his father was a majority shareholder of the magazine's publisher. (PDA: Island of Death) He first got involved with the Doctor's affairs through his colleague, Sarah Jane Smith, when her editor provided her with Jeremy as a photographer for a story that the editor didn't take seriously. Although Jeremy ended up accompanying the Doctor and the Brigadier when they had to travel to another planet to rescue Sarah, this was only because the Doctor asked Jeremy to take his toolbox into the TARDIS and forgot to tell him to stop. (BBCR: The Paradise of Death)

It was hinted that he lost his memory messing around with one of the Doctor's inventions and that he became the antagonist "John Doe", who was manipulated by powerful psychic aliens to assist in their escape from a prison dimension before their plans were thwarted by the Sixth Doctor, their other agents killing John Doe before the Doctor could meet him face-to-face. (PDA: Instruments of Darkness)