Giacomo Casanova
From Tardis Wiki, the free Doctor Who reference
Giacomo Girolamo Casanova de Seingalt, better known as Casanova, was a famous Italian writer, adventurer and womanizer.
According to the Eleventh Doctor, Casanova and an unspecified incarnation of the Doctor had made a bet, which the Doctor lost. He then owed Casanova a chicken. (DW: Vampires of Venice)