HE'S SHORT. HE'S MUSCULAR. HL HAS A Cagney snarl and a Chaplin waddle. He has a two-picture deal with MGM, and he has his face on a billboard overlooking Sunset Boulevard. For a 5-year-old brown, white and black Jack Russell terrier, Barkley is having a nice Hollywood career.

Of course if you believe Doree Sitterly, his 38-year-old owner and trainer, Barkley's success—TV roles in the new Burke's Law series and Full House and seven feature films in five years—is attributable to his Method acting style, more Brando than Lassie. "When Barkley is in a scene," says Sitterly, who has been training animals since 1982. "he really lives what's going on. He believes the scene is real."

Barkley has been earning about $250 a day but may be due for a raise. He recently opened to raves opposite Dana Carvey in the comedy Clean Slate, in which he plays a dog with vision problems who perceives everything to be two feet to the left of its actual location and so crashes into walls a lot. Director Mick Jackson enjoyed the matchup. "Dana has that hangdog quality," says Jackson, "and Barkley is a deadpan Buster Keaton type." Barkley fans can catch the pooch again this summer in It Runs in the Family.

The terrier, which lives in West-lake, Calif., with Sitterly, was born in Oregon of less than aristocratic pedigree, according to the Jack Russell Terrier Club of America, which declares that his legs are too short and crooked and his head is too big. That's not how Jackson sees it. "Almost every frame we shot of him is in the movie," says Jackson. "I wish we'd shot more—that dog is like gold dust."