Andrew Edwardson was a human who looked like the Fifth Doctor.
River Song initially met Andrew on one of her adventures. Later, upon discovering that the Doctor would die at the Bumptious Gastropod whilst in his fifth incarnation, River took Andrew from his house to the restaurant. River then replaced Andrew in the Doctor's place, complete with the Doctor's clothes, so when he met Kovarian and Brooke 1 they thought he was the Doctor.
After being chastised by the Maitre D' for treating Andrew as a "human sacrifice", River eventually decided to rescue Andrew. She attempted to replace him with a robot waiter, unconvincingly disguised as the Doctor, and took Andrew into the Bumptious Gastropod's past while it was still a cafe. Finding an unlimited credit slip from the Galactic Century Bank in the Doctor's coat pocket, Andrew bought the cafe and became the owner.
Andrew later met River in the present, after Brooke had seemingly killed the real Doctor. He shared a dinner with River, before she left to confront Kovarian. (AUDIO: My Dinner with Andrew)
In reality, it was a future version of Andrew that had been killed. A future incarnation of Brooke had decided to side with River and turn against Kovarian, taking River's vortex manipulator and travelling back to the Bumptious Gastropod where she convinced Andrew to take the Doctor's place, deceiving him into being killed by her earlier incarnation to correct the timeline. (AUDIO: The Furies)