Casanova

In 1580 Venice, after the Eleventh Doctor realised that Casanova wouldn't be born for another 145 years, the Doctor told Amy Pond and Rory Williams that he didn't want to run into Casanova, as he owed him a chicken in a bet. (TV: The Vampires of Venice) He later claimed to Valarie Lockwood the chicken was repayment for Casanova helping thwart a Sontaran invasion. (AUDIO: The House of Masks)

On Red Rocket Rising, Lucie Miller described the Eighth Doctor as "that bloke dressed like Casanova". (AUDIO: Blood of the Daleks)

In 2005, following the Dummy Massacre, Steve Woolfall responded to Doctor Who?'s request for sightings of the then missing Rose Tyler, reporting that he had seen a girl that looked like Rose in the Grosvenor Museum in Chester that afternoon with a chap that reminded him of "that Casanova bloke". Steve suggested that it might not have been the same girl but that it was strange nonetheless. (PROSE: The Doctor Was Involved in the Dummy Massacre)

Behind the scenes

 * David Tennant played Casanova in the written by Russell T Davies, directed by Sheree Folkson and exec produced by Davies and Julie Gardner. The same miniseries featured Peter O'Toole as Casanova in his later life. In The Christmas Invasion, the blue coat that Tennant wore as Casanova in the miniseries can be seen in the TARDIS wardrobe as the Tenth Doctor chooses his outfit. He was also played by Frank Finlay in an earlier version.
 * A standalone panel by comic artist Lee Sullivan shows Tennant's Casanova meeting the Ninth Doctor and Rose Tyler amidst an invasion of Venice's St Mark's Square by bronze Daleks. As the naturally brown eyed Tennant had wore blue contact lenses in his portrayal of Casanova to match O'Toole, Casanova is accurately depicted with blue eyes.
 * Tennant's role as Casanova was recalled in The Ballad of Russell and Julie, where Catherine Tate, playing Julie Gardner, remarks "We'll get the lovely fellow in from Casanova!" for the role of the Tenth Doctor after Ninth Doctor actor Christopher Eccleston left Doctor Who.
 * David Tennant's role in Casanova was alluded to in the short story The Doctor Was Involved in the Dummy Massacre.
 * The 12-18 March 2005 edition of Radio Times, through sheer coincidence, had Tennant's version of Casanova adorn its cover while also bearing a Doctor Who headline, promoting the then-upcoming debut of Series 1, well before Tennant would be announced as taking over the role.