Robert Knox

Robert Knox was a human who acquired a TARDIS.

Knox acquired his Type 70 TARDIS from a Nekkistani dealer on Gryben.

Knox first met the Sixth Doctor when he was contracted to give humans an alien flu virus to help cure an alien race. During this time Knox also placed a few days in 1828 in a time bubble so he could charge alien businessmen to watch the suffering of the humans in that period. Knox was stopped by the Doctor, who destroyed the time bubble and purposefully infected Knox with the alien virus. (AUDIO: Medicinal Purposes)

Knox failed to find a cure for the alien flu. He ended up doing a deal with an Indo he met on Mercury to prolong his life after the virus had killed him. Knox used a concoction of lavender and bergamot to cover the scent of his decaying body. Posing as Oscar Wilde in 1865 Washington DC, Knox tried to kill John Wilkes Booth to prevent Booth killing Abraham Lincoln. After his scheme to alter history was stopped by the Doctor and Evelyn Smythe, Knox apparently finally died. He escaped, however, in the body of another dead human, riding a train away from Washington under the alias Arthur Conan Doyle. (AUDIO: Assassin in the Limelight)

Appearance
Knox wore a silk cravat. He claimed to have worn a cardigan at the Charge of the Light Brigade. (AUDIO: Assassin in the Limelight)

Behind the scenes
"Robert Knox" shares his name with the who was involved in the Burke and Hare murders. However, the showman is stated in Medicinal Purposes not to be the "real" Knox.