"The Beast," now at the Key, is a shaggy porn fable from Walerian Borowczyk, a former Polish animator who came to international attention with compatriot Roman Polanski at the World's Fair in Brussels and eventually settled in France to direct ostensibly live-action features.

The prototype for this complacently nasty doodle on the subject of bestiality must date from the dawn of language itself. Borowczyk can probably be considered a dirty mind in a venerable tradition, but there's no compelling reason to sample his style of dirty joking.

The basic idea, as always, is to project a male sexual fantasy onto an ingenuous female character. In this case an heiress, played by Lisbeth Hummel, arrives with her aunt at a chateau to meet her intended bridegroom, the weird son of a nervous nobleman. Aroused by erotic sights and drawings, the heroine dreams a prolonged sequence in which a maiden is purseued and ravished by a monster.

Sirpa Lane, last seen as the bad girl of Roger Vadim's "Charlotte," draws even grungier duty as the rape victim, who naturally turns out to be more than the ravisher bargained for. Indeed, the maiden is so insatiable that the poor monster dies of exertion. This typical denouncement seems to arise out of an anxiety as transparent as the rape fantasy that precedes it. Having ascribed a dream of self-degradation to a woman, the male fantasist then accuses her of being a man-killer too.

The dreaming heroine is supposed to escape a bestial union by the skin of her teeth, but the resolution of the framing story is incidental. The movie simply marks time until Sirpa Lane is pictured being chased, disrobed, raped and then overjoyed at the experience of sexual excess.

Hers may be remembered as one-of-the weirder careers of the '70s.[WORD ILLEGIBLE] doesn't quite forget an actress who specializes in runaway nympliomania especially in concert with an actor in a monster suit, but who needs this form of exhibitionism in the first place? If you thought a porn version of "King Kong" would be funny, "The Beast" may persuade you otherwise.