Fox, FX and Gracie Films will be premiering the 600th episode of The Simpsons, "Treehouse of Horror XXVII," this Sunday at 8/7 p.m. CST on FOX. Featured guests include: Drew Carey, Donald Fagan, Sarah Silverman and Judith Owen. Matt Groening continues the longest-running animated comedy series with a special milestone episode featuring new characters, as well as past favorites returning such as Frank Grimes. Based on the preview coverage it looks more like the ghost of Frank Grimes, but with The Simpsons being a fictional-based cartoon, all bets are off with the Treehouse of Horror. This year the show is featuring a special virtual