Considering all the Elvis-is-alive conspiracy theories, having the King battle a soul-sucking Egyptian mummy in an old-age home is actually not so far-fetched. Having him do it with the assistance of a wheelchair-bound black man who thinks he's JFK? Okay, that's a bit out-there. But Don Coscarelli's horror comedy is more tender than tacky, and I can't help falling in love with Campbell's charming portrayal of an over-the-hill Elvis. EXTRAS What would the real Big E think of the movie? Find out via a hilarious ''commentary'' from the King on which he munches popcorn and informs us, ''I did 33 pictures. Never did any horror pictures, though, except ''Harum Scarum'' had some scary parts.''