Strangely/ironically/whatever... the XXX film version: The Erotic Adventures of Candy, starring buxom Carol Conners in the title role (and prominently featuring John Holmes), follows the Terry Southern novel almost perfectly (in terms of storyline). I read the book just after its initial release -- not very good; don't know why such a brouhaha arose from it -- and can't remember any reference to Candy being an alien. That must have been an added conceit to this particular film version.

... Reed