Fairly accurately described as “’Sesame Street’ meets ‘South Park,’” the hit musical “Avenue Q” features a Muppets-inspired cast of characters saying and doing the naughtiest things. But even “South Park” is bound by certain cable-TV rules and regulations. Whatever is more foul-mouthed and sexually explicit than “South Park,” that’s “Avenue Q.”

After sold-out runs in New York and on the road, Horizon Theatre’s new “Avenue Q” is one of the first regional productions of the show (book by Jeff Whitty, music and lyrics by Robert Lopez and Jeff Marx). Briskly staged by director Heidi Cline McKerley and nimbly performed by an ensemble of 8 actors/puppeteers/musicians, it’s decidedly irreverent and risqué – and downright irresistible, coming from so many adorable hand puppets (designed by Russ Walko).

You may never again think of “Sesame Street” quite the same way. Conjuring images of Bert and Ernie (here, Rod and Nicky) and Cookie Monster (here, Trekkie Monster), among others, “Q” skewers everything from racial prejudice and sexual preference to Internet porn and the meaning of life. Some of the song titles tell it all: “It Sucks to be Me,” “You Can be as Loud as the Hell You Want (When You’re Makin’ Love),” “What Do You Do with a BA in English?”

Most of McKerley’s actors not only operate the respective puppets they’re playing, but they also act out their roles using the rest of their bodies, with their own facial expressions. Some inhabit several puppets, or take turns playing the same one in different scenes. Where to look for the biggest laugh – at the puppet or at the actor – is hard to call, and that’s no small part of the fun in itself.

Those portraying the human characters pitch in and go the extra mile, too. When Leslie W. Bellair, for instance, isn’t playing a feisty Asian wife and street-corner psychotherapist named Christmas Eve (delightfully and genuinely so, without a trace of caricature or condescension), or when Spencer Stephens isn’t on view as Gary Coleman (yes, that Gary Coleman), they periodically make their way up to a corner loft of the stage, where they take to instruments and accompany music director S. Renee Clark’s lively three-piece band.

And let’s hear it again for that sister act of scenic designers, Moriah and Isabel Curley-Clay (“Superior Donuts,” “Shooting Star”), for yet another evocative set, a city block of apartment fronts. During the blackouts and scene changes, lighting designer Mary Parker uses a funky black light to accentuate the graffiti.

The humor in the show is hardly high-brow and the life lessons aren’t very deep, either. It helps that the winning Nick Arapoglou puppeteers the protagonist, whose comical search for a purpose in his life leads him to the joy of helping others. It’s as basic as learning your ABCs on “Sesame Street,” but no less funny and sweet all the same.

Theater review

“Avenue Q”

Grade: B+

Through July 3. 8 p.m. Wednesdays-Fridays; 3 and 8:30 p.m. Saturdays; 5 p.m. Sundays. $20-$50. Horizon Theatre, 1083 Austin Ave., Atlanta (in Little Five Points). 404-584-7450. horizontheatre.com.

Bottom Line: Puppets gone wild.