CAST: Jack Black, Ana de le Reguera, Héctor Jimenez, Richard Montoya, Peter Stormare, Efren Ramirez, Troy Gentile, Carla Jimenez

DIRECTOR: Jared Hess

SCREENWRITERS: Jared Hess, Jerusha Hess, Mike White

He’s fat, he’s vulgar, he’s manic and, on occasion, he’s howlingly funny. He’s also a fine, natural-born actor. Who is he? He’s Jack Black, and he’s really the only reason for you to see this sporadically amusing mess of a movie.

You’d expect something classier and more imaginative from the key creators of “School of Rock” and “Napoleon Dynamite.” But “Nacho” is a shoddy amalgam of slapstick and sentimentality, co-written and directed by “Dynamite’s” Jared Hess with minimal concern for characterization, pace or coherence.

Black plays Ignacio, a mucho simple cook in a rundown Mexican monastery cum orphanage, a man whose plumpness is a mystery, since the good friars give him so little money for food that everyone, including Ignacio’s beloved orphans, are on a steady diet of putrid gruel. Perhaps the reason the pudding-hearted chef loves those little orphans so much is that he strongly identifies with them--particularly one inexplicably obese boy. For the fact is that Ignacio first set foot in the monastery when he himself was a chubby kid whose dad and Scandinavian-missionary mom had recently died and presumably gone to heaven.

Eventually, Ignacio the Man decides to enlist in the league of the Lucha Libres, those virile, fearless, get-rich-quick professional wrestlers who are revered by countless Mexicans. The friars, alas, consider wrestling sinful and would probably boot Ignacio out of the monastery if they knew his secret, thus separating him from his cherished tots, not to mention Sister Encarnacion, a recent arrival at the orphanage for whom he has the hots. (She’s played by Ana de le Reguera, who provides a happy answer to the question, is it possible for a nun to be a babe?) So that’s why Ignacio wears a mask and calls himself Nacho Libre when he bounces into the ring.

Violent and repetitive as they are, it must be said that there is something fascinating about these matches. And that something is the unique presence of Jack Black. Sweetly, dumbly, valiantly enduring extreme punishment at the hands and feet and, yes, heads of pitiless hulks and vicious midgets, Black is bizarrely balletic--a pudgy Baryshnikov floating gracefully through the air in his flashy, trashy tights. There’s even a cockeyed grace about him when he’s crunched and knocked flat on the mat. You know he’ll get right up and that he will survive.

But will he finally win a match, receive public acclaim, put decent food on the kids’ plates, and exchange vows with his favorite nun? Are you kidding?