This is nuts,'' declares killer doll Chucky (voiced by The Lord of the Rings' Brad Dourif for 16 years now), ''and I have a very high tolerance for nuts.'' That tolerance is tested in this fifth round of the winking, semi-subversive horror franchise, Seed of Chucky, which pits the demon moppet, his sexually confused son Glen (ex-hobbit Billy Boyd), and squeeze Tiffany (voiced by Jennifer Tilly) against...actress Jennifer Tilly, who comes upon the clan while shooting, yes, a Chucky movie. Scream it ain't: The nonstop meta-jokes (including an inspired John Waters cameo) coagulate rather than spurt. But Tilly-as-Tilly, playing a C-lister who offers herself to Redman for the Virgin Mary role in his self-directed Bible epic (no foolin'!), deserves a medal for sportsmanship. By far, the most shocking carnage is Tilly carving up her persona. What a doll.