Little Stewie sits in his highchair playing with something that looks like a toy ray gun. It is, in fact, the mind-control device he is inventing.

''Stewie, I said no toys at the table,'' his mother says as she takes it away.

''Damn you, vile woman!'' Stewie answers in his plummy British accent, his eyes narrowing with his sinister thoughts. ''You've impeded my work since the day I escaped from your wretched womb. When you least expect it your uppance will come.''

The misfit child in a typical New England family, Stewie the Killer Baby may be the most intelligent and wry television character since Frasier Crane. They even have the same hairline, not to mention common-sensical fathers who will never fathom their urbane sons. Unlike Frasier, though, Stewie shoots at his mother from a high-tech weapon hidden in his tuna sandwich, all part of his dastardly plot to take over the world. A baby can dream, can't he?

Stewie is the funniest character in the risky, rude, hilarious new animated series ''Family Guy.'' And with the once-sterling ''Frasier'' in a slump this season, ''Family Guy'' stands to become the best satire of all-American dysfunction next to ''The Simpsons.'' (''Family Guy'' will have a special preview on Fox after the Super Bowl on Sunday night and begin its run in March.)

If comparisons to ''Frasier'' and ''The Simpsons'' seem equally comfortable, that suggests how well-written ''Family Guy'' is, and how limiting it would be to see the series merely as part of the copycat glut of prime-time animation (at least seven shows and counting). Like ''Frasier,'' the series is a satire of class and culture in America. And like ''The Simpsons,'' it takes full advantage of the freedom animation offers: humans act on their ids and worst impulses yet remain likable. A bumptious, irresponsible Dad like Homer Simpson is lovable only because he is a cartoon, kept at a nonthreatening distance from reality (or so we tell ourselves).

Whatever its similarities to other shows, ''Family Guy'' feels wholly original. Stretching humanity to the breaking point, the series reflects and at the same time explodes the image of the American family. Today that image is more likely to be dysfunctional than idealized, and to be shaped by movies and television as much as by real-life neighbors. So the series' opening song echoes the off-key Archie-Edith duet that began ''All in the Family.'' Sitting around the piano are Peter Griffin, the portly, bumbling guy of the title, and Lois, his kind but nasal-voiced wife, singing, ''Where are those good old-fashioned values?''

Laden with such swift jabs at pop culture, the first episode begins with the Griffins watching ''The Brady Bunch,'' perfectly drawn right down to Mr. Brady's ludicrous 1970's permed hair. In this version, when Greg Brady tells a lie his father says, ''I'm afraid your punishment will be four hours in the snake pit,'' and Greg disappears through a trapdoor in the kitchen floor. His sister Jan is locked in ''the chamber of fire,'' a blazing closet.

The Brady Bunch from hell is a pretty good setup for ''Family Guy.'' Peter is underemployed and basically underqualified for life. His 13-year-old son, Chris, shows every sign of becoming a beer-swilling oaf to make his father proud. Meg, the frumpy teen-age daughter, dreams of collagen injections for her lips. Brian is the family's talking dog, who raps Peter on the nose with a newspaper to knock some sense into him. (Along with Dogbert on the new series ''Dilbert,'' that makes too many smart talking dogs on television.)

Visually, everyone is drawn in broad strokes except Stewie, whose head is shaped like a football. And since the other Griffins have flat American voices, there's no explanation for Stewie's accent except an overdose of old British movies. (Seth MacFarlane, the 25-year-old who created ''Family Guy'' and does Stewie's voice, has declared his affection for Rex Harrison. But Stewie's sense of melodrama, as well as his name, brings him closer to the B-movie actor Stewart Granger.)

If attempted matricide isn't rough enough, ''Family Guy'' takes a politically incorrect approach to ethnic jokes. Some work: when a black woman wearing a kerchief appears outside the window offering pancakes, Peter points her out as one of those ''Jemima's witnesses'' who are always showing up. Less inventive is the ''G.I. Jew'' doll who complains about bagels.

But a few misfired jokes are worth it; most of the risks in ''Family Guy'' pay off. In the first episode, Peter loses his job and soon gets an erroneous welfare check worth $150,000. For a time he lives luxuriously in the land of welfare fraud. Nothing is out of bounds as this series gleefully undermines family sitcom values.

FAMILY GUY

Fox, Sunday night at 10 (time approximate, following Super Bowl)

(Channel 5 in New York)

Seth MacFarlane and David Zuckerman, executive producers; Mr. MacFarlane, creator; Craig Hoffman and Danny Smith, supervising producers; Sherry Gunther, producer; Mike Barker, Ricky Blitt and Matt Weitzman, co-producers; Gary Janetti and John Riggi, consulting producers; Mike Henry and Andrew Gormley, staff writers. Produced by 20th Century Fox Television.

WITH THE VOICES OF: Seth MacFarlane (Peter Griffin, Stewie Griffin and Brian Griffin), Alex Borstein (Lois Griffin) and Seth Green (Chris Griffin).

Photo: In the dysfunctional Griffin family of Fox's ''Family Guy,'' the baby and dog are the smartest members. (Fox)