Brian (Echo Chamber)
Brian once called into the radio show the Fifth Doctor presented. He only listened into the show to disagree with them. He didn't trust the Pellent Glommeration, and thought that the Doctor wasn't listening to him. (AUDIO: Echo Chamber)
The Doctor would eventually discover that Brian, along with many other people throughout history who looked like him, were caused by a group of Time War Daleks who — while on a mission to prevent the rise of Time Lord society on Gallifrey — created a time distortion which created alternate versions of themselves as four un-mutated Kaled people. This time distortion also caused there to be multiple copies of these four Kaleds at various points throughout time and space. (AUDIO: Effect and Cause)