Not to split hairs, but "An American Werewolf in London" suffers from schizophrenia. Gratuitous gore prevents this monstrous movie from becoming the competent comedy it might have been.

Director and writer John Landis (also director of "Animal House") doesn't have the skills to scare the pants off you, so amid hilarity, he douses his howling hero with warm, wet blood. It oozes, it spurts, it gurgles, it pours. Then, abruptly, it's joke time.

A funny thing happens to David Kessler and his buddy Jack Goodman on their three-month European vacation. On the lovely, lonely moors of northern England, the two young men meet their supernatural destiny. Goodman, played by Griffin Dunne, becomes a moonlit meal for a werewolf; Kessler, played by David Naughton, receives a severe raking from its beastly claws, thereby sealing his future in lycanthropy.

The bloodthirsty needs of horror fans momentarily sated, the film goes for the gooseflesh, raising anxiety levels by rendering the cute and adorable eerie. Kessler, for example, is awakened in a London hospital by the voices of Miss Piggy and Fonzie Bear, which is really Frank Oz, who in this film is playing Mr. Collins of the United States Embassy in London. Scenes later, Miss Piggy's back with a starring role as a Nazi in one of Kessler's nightmares, which are symptoms of his wolfishness to come.

Even Mickey Mouse, Walt Disney's best little man, cannot halt the carnage on the big night. Like a failed plastic amulet, the sappy rodent simpers while Kessler achieves an altered state by the light of the waxing moon. His metamorphosis, painstakingly created by Rick Baker of "Star Wars" bar-scene fame, is very like the one performed by William Hurt as he made a monkey of himself. And apparently, when one transmogrifies, it's all the rage to awake in a zoo having supped on the run the night before.

With six fine Brits in his tummy, Kessler is feeling up for a nude romp through the zoo, where he borrows balloons from a little boy in lieu of a fig leaf. He steals a woman's coat, and suddenly it's Uncle Miltie time. Naughton, who can claim "I'm a Pepper" in real life, calls on his most cuddlesome commercial qualities here.

Both Naughton and costar Griffin Dunne, who comes back to life for the rest of the film, are believably unbelievable as buddy and the beast. Dunne's terrific as the devoted, decomposing sidekick, an undead Hardy Boy who patiently urges his old pal on to suicide so that he may rest in peace.

Despite credible performances by Dunne, Naughton and the rest of the cast, Landis' "American Werewolf" has bitten off more than it can chew.

AN AMERICAN IN LONDON -- At the ABC Drive-In, AMC Skyline, Jenifer, Laurel Drive-In, NTI Landover Mall, Roth's Randolph, Roth's Tysons Corner, Showcase Andrews Manor, Showcase Fair City Mall and Springfield Mall.