Little Shop of Horrors

A musical by Howard Ashman (book and lyrics) and Alan Menken (music). Based on the film by Roger Corman. Directed by Mr. Ashman.

Moving right along the Off Broadway trail, one comes upon the WPA Theater, making comic little shock waves at the Orpheum on Second Avenue. According to a WPA higher-up, its initials stand for ''We'll produce anything.'' Which may explain ''Little Shop of Horrors,'' a musical spoof of a Roger Corman spoof of horror movies (in the days before the genre degenerated into vicious sadism).

Collaborators Howard Ashman and Alan Menken have written the words and music for a burlesque chiller about a lowly flower shop assistant named Seymour (Lee Wilkof), whose horticultural wizardry produces a strange new flytrap plant. The plant and its attendant publicity transform the derelict shop into a floral bonanza. Seymour's sudden fame and good fortune embolden him to romance fellow employee Audrey (Ellen Greene), the fair flower of his heart. Seymour has already named his botanical wonder ''Audrey II.''

But to expand a one-time margarine commercial, ''You can't fool around with Mother Nature.'' It turns out that Audrey II is a sanguinary sprout satisfied only with human blood. Full grown, it resembles a cross between a bloated poppy pod and the business end of a shark. Nor can Audrey distinguish between good guys and bad guys. Anyone is a prey for its conspicuous consumption. Poor Seymour!

As a broad lampoon, ''Little Shop of Horrors'' is more mirthful than frightful. The cast directed by author Ashman enters into the mock macabre spirit of the occasion with the desperate seriousness required by such antics.

The emporium's voracious star attraction receives a bravura behind-scenes performance from puppeteer-manipulator Martin P. Robinson and singer Ron Taylor, whose rendering of ''Feed Me'' qualifies Audrey II as the most reverberant bass-baritone ever to spring from a botanical garden of horrors.

Excuse me while I feed my plants.