Casanova

Giacomo Casanova was a famous Italian writer, adventurer and womaniser.

According to the Eleventh Doctor, Casanova and an unspecified incarnation of the Doctor had made a bet, which the Doctor lost. He owed Casanova a chicken. (TV: The Vampires of Venice)

Behind the Scenes

 * The bet may be a reference to the fact that in 2005, David Tennant portrayed Casanova in the BBC miniseries based on his memoirs that was also created by Russell T Davies and Julie Gardner. This resulted in him being someone they wanted to be the Tenth Doctor once Christopher Eccleston stepped down. (CON: ''New New Doctor)
 * In TV: The Christmas Invasion, the blue coat that Tennant wore as Casanova can be seen in the TARDIS wardrobe as the Tenth Doctor chooses his outfit.