Baris was the Doctor's number one fan. He spent most of his life searching for his hero. Before he met the Doctor, he had Mega Plastic Surgery to make him look just like him, from voice to even having a second heart fitted.
During the events on Planet 1, he helped the Tenth Doctor escape and save Donna Noble. He was chased around the planet by the hunters who thought he was the Doctor. Although he was the Doctor's biggest fan, he didn't know the name that the Tenth Doctor gave to his "brainy specs." (PROSE: The Doctor Trap)