By Nicholas Fonseca
Updated March 10, 2006 at 05:00 AM EST

The inhabitants of Little Britain — the joyously off-kilter, poorly behaved country at the center of Matt Lucas and David Walliams’ sketch-comedy series now entering its third season on BBC America — are grotesque ne’er-do-wells with proclivities manufactured for maximum offensiveness. And they have hardly softened with age.

Are you fat? Look out for Bubbles (Lucas, who, along with Walliams, plays nearly every major character), a shrill nymphomaniac who resembles an obese version of the ’80s Bette Midler and enjoys dropping trou to expose every inch of her cellulite-ridden 280 pounds. Are you gay? Then you’ll wince at Sebastian, who sings a version of Christina Aguilera’s ”Beautiful” to the prime minister (guest star Anthony Head, of Buffy the Vampire Slayer, gamely traipsing through in a studded leather G-string).

Are you old, homely, single, hygienically challenged, or afraid of frogs? Then you’re in the line of fire too, as Lucas and Walliams satirize their homeland in set pieces linked together by the perfectly pompous voice-over of Doctor Who’s Tom Baker. Potty humor also gets a major workout in their twisted world: Racist biddy (and kidney-transplant patient) Maggie spews copious vomit when she learns she’s received an Indian man’s organ; dementia-stricken Mrs. Emery empties her bladder in public, portraying the sensation so realistically you’ll swear you can smell the urine from your living-room couch.

For all this hilarity (which is oddly ebullient in its celebration of outcasts), Britain — much like SNL and MADtv — can’t always sustain the laughs. Lucas’ portrayal of Thai mail-order bride Ting Tong Macadangdang approaches the bigoted vulgarity of Mickey Rooney’s Japanese neighbor in Breakfast at Tiffany’s. And I still don’t get the appeal of slovenly Lou and his mentally challenged friend, Andy. Their misadventures just aren’t funny; in fact, I’d say they’re downright mean-spirited, like when Andy calls in to a TV game show and fails to comprehend the host’s simple instructions. Scenes like this are a shame, because for all its filthy, improper put-ons, Little Britain succeeds most brilliantly when it captures — without judgment — the free-spirited glee of life as a social misfit.