R2-D2

Tegan Jovanka contemptuously referred to her former companion Nyssa's servo robot Loki as R2-D2. (AUDIO: Cobwebs)

Andy Hansen once told a joke to Erimem which involved R2-D2 in the punchline. (PROSE: Arrrr...)

The Tenth Doctor once introduced his "associates" Cindy Wu and Gabby Gonzalez as "Artoo and Threepio", much to their irritation. (COMIC: )

Behind the scenes

 * R2-D2 is a character in the Star Wars series and the constant companion of C-3PO.
 * ITV's animated comedy sketch series featured a science fiction parody of  entitled Galaxy Idol, featuring R2-D2 as a contestant who is rejected by Simon Cowell whilst the Fourth Doctor, himself a judge, remains silent. Following R2-D2 is a performance by a grey Dalek.
 * In the Star Wars: The Clone Wars episodes "A Test of Strength" and "A Necessary Bond", David Tennant voices the character of Huyang who works closely alongside R2. (R2 also helps repair Huyang in "Bound for Rescue", but Tennant has no lines in the episode.)
 * Russell T Davies has jokingly referred to his second stint showrunning Doctor Who as "RTD2".