Atmosphere converter
From Tardis Wiki, the free Doctor Who reference
The Eleventh Doctor told Valarie Lockwood that he blew up the Sontarans' atmosphere converter thanks to Casanova distracting one of the most decorated Sontaran generals in history. Because of Casanova's help, (AUDIO: The House of Masks) the Doctor owed him a chicken. (TV: The Vampires of Venice)