We all know My Fair Lady, the play/movie about the lower class woman who learns how to speak and act like an aristocrat; but how about a turnabout on this idea? The result would be called, naturally, My Foul Lady, and it would be about an aristocratic young woman from a titled family of the landed gentry in the United Kingdom, and she is joining an elite intelligence/law enforcement squad that investigates organized crime and terrorist cells and such, and as her upcoming assignment is to infiltrate some very gauche lower class criminal underground group, she must learn how to talk and act just like the criminal types from the gutter; and to teach her there is some retired underworld mobster from the wrong side of the tracks, and he teaches her all about how to talk and behave in the seedy underbelly of London's lawbreaking brutes and scum. And since there is such a rogues gallery of people she must impress and rub shoulders with, she must learn all sorts of specialized lexicons, dialects and vernacular from all kinds of criminal activities from drugs to robberies to assassin squads to extortion rackets and terrorist groups, etc. And after much work and practice in acquiring her new skills, to prove her abilities she insinuates herself into some underground illegal snake fighting gambling thing, and she impresses everyone she meets, who all comment on how low and seedy and sinister and shifty and such she appears. And then she is deemed ready and able to brave the rough-and-tumble netherworld of the lowest-down, most classless environment imaginable, for which she is now perfectly suited thanks to her grueling training in the high art of the low down by our slimy Henry Higgins stand-in.
(Of course, all of the criminal types will be extra gauche and exaggerated for toughness, etc., just like in the Bugs Bunny cartoons, just to make everything as ridiculous and overly mannered as possible for comedic effect. And the Henry Higgins opposite guy would be some master criminal/super villain type like Gru from Despicable Me or Simon Bar Sinister.)