Bat Boy, taking its Bay Area bow in an energetic, nearly flawless production by Palo Alto's TheatreWorks, is indeed another mischievous, savvy, and pop culture-saturated off-Broadway musical surprise hit. Although slightly more modest in scale than Urinetown at the American Conservatory Theater, it's hard to imagine any of the several regional theaters now producing a version of Bat Boy getting it more right than director Linda Goodrich and her colleagues and cast.

Having descended deep into the bowels of a West Virginia cavern, three spelunking teens from the plaintively named town of Hope Falls spark up a celebratory hooter only to discover in its glow an inarticulate humanoid creature running around naked and squeaking like a bat (the quite articulate and altogether impressive Justin Greer). Initially charmed (who wouldn't be?), they're put off when the thing bites one of them. They drag it back to town and present it to a confused sheriff (Eric Wenburg) who decides to hand it over to the town veterinarian, Dr. Parker (David McDonald).

Mrs. Parker (Heidi Blickenstaff) and daughter Shelley (Molly Bell) insist on adopting and raising the creature, naming him Edgar. Dad is loath to go along for a number of reasons, not all of them immediately understood – but clearly he's already in hot water with the touchy townsfolk for failing to halt a blight affecting the cows in this sad-luck former mining town. He relents only after his frigid wife promises recompense in the sack. Soon (in a winning spoof of My Fair Lady) Mrs. Parker has Edgar speaking in perfect BBC English. Now a proper gentleman (and, as such among rubes, more of a freak than ever, really), Edgar eagerly wishes to win over his reluctant neighbors by having a formal coming out to the community, a sort of bat mitzvah at the revival tent.

But dark secrets cloud this family affair, including Edgar's guilty taste for blood – which may just run in the family. Moreover, in the minds of the townsfolk, resentments fester and questions remain. Is the creature inherently evil? Is he behind the plague decimating the local livestock? And even if who-the-hell knows, what self-respecting mob waits for all of the facts before sharpening its pitchforks?

Throughout the rock-, rap-, country-, and show-tune-laden story line (bolstered by collaboration with composer-lyricist Laurence O'Keefe), Greer's entirely sympathetic and winsome misfit runs the gamut from pitiful to playful to heroic, while gracefully rendering the daunting physical gestures and acrobatics of a character who's half bat. The whole Parker family is also excellent, the actors delightful in their characterizations and comic timing. The enjoyable cast features many fine turns, including C. Kelly Wright's standout as the rollicking itinerant minister who presides over the revival meeting and its boisterous gospel number, "A Joyful Noise."

Achieving the very heights of silliness while remaining grounded in a compelling story is no mean trick, and Bat Boy manages it remarkably well. Not every conceit feels as fresh as the Lion King-like parade of animals in joyful heat, decked out ridiculously and to great effect in Allison Connor's costumes. The scenes involving the townsfolk and their plotting tend to revolve around the usual yucks at the expense of the yokel without adding much. But even with its occasional tendency to fall flat or go a little too over-the-top, Bat Boy remains a smart and assured ride, shrouded in scenic designer Andrea Bechert's impressive subfusc set – which weds versatility with a playful appeal reminiscent of Sesame Street, or maybe Iron Maiden – and buoyed by musical director William Liberatore's fine and ferocious five-piece rockestra.