“Little Shop of Horrors” is also, of course, great fun, and never more so than at New Rep, where simple, thoughtful production values rule. Peter Colao’s set shows the alley in back of the run-down flower-shop block, with tires scattered here and there, “Flats Fixed” spray-painted on one faded brick wall, a shopping cart, a trash can, excess garbage lying about, and a chalk outline on the pavement that a wino will eventually appropriate for his night’s rest. The two center sections rotate to display the interior of Mushnik’s Skid Row Florists, a dull-looking affair with a counter, a cash register, a calendar, a bulletin board, a couple of hanging plants, and no customers. (It could be the prices: When someone does come in, $100 gets him just eight wilted-looking American Beauty roses from the fridge.)

Business is so bad, Mushnik is planning to lay off his two employees, Seymour and Audrey, and close up shop — until Seymour produces the fatal flytrap that he found in the aftermath of a total eclipse of the sun. He’s named it Audrey II, and, in the first of its four New Rep incarnations, it’s puppet-size and cute as a button as it salivates at the sight of Seymour’s blood. Actually, all four Audrey IIs are adorable, even the last one, with its leafy ears and pouty grin; voiced by Timothy John Smith and manipulated by Timothy P. Hoover, it’s as big as a warthog but moves like a polo pony.

The human cast members are also just right, both as actors and as singers. Pfeil is a nerdy Seymour in plaid shirt and baseball cap who wears his longing for Audrey on his sleeve — and not just because Molloy’s brassy-voiced blond bombshell comes to work every day in a black sheath and high heels. They make a shy, affectionate couple. Farwell’s crusty, calculating florist is almost likable; so is Mootos’s leather-jacketed, motorcycle-riding dentist (the girls call him “the leader of the plaque”), whose real crime is that he’s in love with himself and not Audrey. It’s painful to see the pair of them go down Audrey II’s maw.

But in their plaid or pleated skirts, Fogarty, Hoffman, and Zweil keep “Little Shop” upbeat, whether they’re celebrating “Skid Row (Downtown)” or doing a 6/8 stroll. If any part of humanity can survive Audrey II, it will be ’60s girl groups. Jeffrey Gantz can be reached at jeffreymgantz@gmail.com.