This topic might have a better name.
Should this be Song (I Went to a Marvellous Party) despite it not being his real name?
Talk about it here.
"Mr Song", also known as "The Doctor" was a renegade member of the ancient Sanukuma species, also known as the First Race. He tried to stop his race's spore ships and allied himself with the group calling themselves the "Rulers of the Universe". With their help, he abducted River Song and tried to convince her that he was in fact an incarnation of the Doctor. (AUDIO: Signs, The Rulers of the Universe)