Mary Poppins is a much loved Disney musical about a magical nanny who helps a family come together or some such nonsense. There are songs and bad British accents from Dick Van Dyke. In the world of The Simpsons, Marge is so stressed from having to deal with her nightmarish family that her hair begins falling out. Thus begins the quest to get a nanny, and thus begins the parody of Mary Poppins. Sherry Bobbins (who we're assured is an original creation, like Rickey Rouse and Monald Muck) shows up and begins to make things better by teaching the kids to do things half-assed and singing them songs about a boozehound named Barney. The episode very much plays against the wholesome, happy nature of the original, right down the conclusion when Sherrys best efforts cant stop Bart from whipping cupcakes, and she devolves into drunkenness. The Simpsons rally her spirits by singing about how theyre happy with things the way they are, as lousy as they may be. Then Bobbins is sucked into an airplane engine. Hey, if you are going to parody Mary Poppins, go big or go home.