Last night was the 19th annual "Treehouse of Horror" episode on The Simpsons . As mentioned before, they spoofed the opening credits of Mad Men for one segment, and for the final bit, they spoofed the Peanuts classic It's the Great Pumpkin, Charlie Brown! In it, Milhouse — who plays the Linus character — believes that the Grand Pumpkin will rise on Halloween and give candy to kids who truly believe in him. Lisa is supposed to be Sally, but instead of being a ghost, she dresses up in what Milhouse thinks is a witch costume, but she corrects him, telling him that she's actually a Wiccan . Clip above.