An early Halloween treat on “Supernatural” tonight (9 p.m., CW). Paris Hilton plays “a monster who takes the form of Paris Hilton.” Series creator Eric Kripke told EW, “it’s a fun, irreverent episode about modern celebrity.”

“We had our wish list in the room of who would be the best spokesperson for a satirical monologue on modern celebrity and Paris Hilton was at the top of the list. We never expected in a million years that she would do it, but I spoke to her and she got the joke immediately. . . I give her a lot of credit for being a hell of a good sport. The fact that she was game to play the part speaks volumes about her sense of humor.”