Many references to Shakespeare's play "King John," including the episode characters: Leroy John (origin "le roi," the king, Fr.) Artie John, King John's son, Prince Arthur Falconbridges, father and son
The title of the episode "And Rarest Parts" references "The Tragedy of King Lear": "Men of choice and rarest parts."
Sebastian's undercover identity as an incomprehensible Scot named Scott was likely inspired by the movie Trainspotting.