Chuckle Brothers

Gwen Cooper once derisively called Jack Harkness and Ianto Jones "The Chuckle Brothers". (TW: Children of Earth: Day One)
 * Though not stated in the episode, the name almost certainly referred to a pair of real-life British comedians.

Behind the scenes

 * Among the Chuckle Brothers' many comedy stage shows was a Doctor Who spoof entitled Doctor What and the Return of the Garlics.