The holidays have always been an occasion to get together with old friends, so a new movie with Kermit, Miss Piggy, Fozzie and the rest of the gang—the first for the late Jim Henson’s stable of creations in twelve years—is entirely appropriate to the season. Fortunately the reunion is a happy one. “The Muppets” improves on their last outing, “Muppets from Space” (1999), by a quantum leap. A jovial tribute to the spirit of the old television series that’s witty without being cynical and warm without going gooey, it’s a real Thanksgiving treat.

The movie starts with a new character—Walter, a Muppet introduced as the unlikely brother of gangly Gary (Jason Segel, who also co-wrote the script). They live in tiny Smalltown and are near-inseparable buddies, but Gary’s managed also to have a long-term romance with chirpy schoolteacher Mary (Amy Adams), whom he’s taking on a bus trip to L.A.—a cherished dream of hers—to celebrate their tenth anniversary. At the last minute, though, Gary invites Walter to tag along; he’s a huge fan of the Muppets, you see, and this will be his chance to visit their famous studio. But that turns out to be a run-down shambles presided over by a single disinterested tour guide (Alan Arkin), and worse, Walter overhears that it’s about to be sold to greedy oil man Ted Richman (Chris Cooper) unless ten million dollars can be raised to keep it in the Muppets’ hands.

That cues a mission on the trio’s part to persuade the initially reluctant Kermit to reassemble the old gang and put on a telethon to raise the needed cash. They rescue Fozzie from doing stand-up in a ramshackle Reno casino, lure Gonzo from his successful plumbing business, and remove Animal from his anger-management group, where his sponsor is none other than Jack Black. To hurry things along, they collect the others, in one of the movie’s many self-referentially cinematic jokes, “in montage.” The only holdout is Miss Piggy, on the staff of Vogue Magazine in Paris, where they all travel in a car “by map” (just tracing the route on paper) to speed things up and wind up driving onto the beach at Cannes from the sea. She’s still piqued that Kermit’s never told her what’s in his heart.

Cutting to the chase, they persuade a reluctant TV exec (Rashida Jones), who quickly needs to fill a hole in the schedule occasioned by the sudden cancellation of the kid show “Punch Teacher,” to book their telethon. All chip in to renovate the theatre and rehearse their acts, and to solve the problem of getting a celebrity host, Piggy—who’s shown up at the last moment—simply kidnaps Mr. Black, who performs his function tied to a chair. Of course the evil Richman tries to put the kabosh on their efforts. Meanwhile Gary must at long last commit to Mary and Walter has to accept his rightful place with the other Muppets.

The scenario doesn’t sound all that inventive, but that’s precisely the point: it serves as an excuse for the movie to become an expanded version of the old variety half-hour, with backstage banter occasionally giving way to the onstage acts. Segel and his co-writer Nicholas Stoller do a nifty job of capturing the wacked-out tone of the old shows, with their mixture of groan-inducing old standards and sassy self-aware put-downs, all the time remaining cheerfully inoffensive. A small army of guest stars from Mickey Rooney to Selena Gomez pop in for quick cameos (some, like Neil Patrick Harris and John Krasinski seeming pretty obvious choices and others—James Carville?—not so much). And there are musical numbers—pop classics like “We Built This City” as well as a few fine new tunes by Bret McKenzie—that succeed in replicating the goofy tone of the ones you’ll remember from years ago, though the rap concocted for Cooper (complete with bouncing-ball lyric captions) is a bit too weird even in this environment.

The human performers—leads Segel and Adams in particular but the others as well—fit perfectly into the Muppet universe (something that’s not always the case—some episodes of the TV show featured guest stars who were all too uncomfortable working with the puppets). And the Muppeteers—Steve Whitmire, Eric Jacobson, Dave Goelz, Bill Barnetta, David Rudman, Matt Vogel, and Peter Linz—bring all the old characters alive again. The movie even gets the amusingly cheesy look of the old show right—and a passing jab at 3D reminds us how lucky we are that the movie isn’t in it.

Like all reunions, this one has moments when it gets a little slow. But overall director James Bobin keeps it perking along. The result is a sprightly, genial affair that should delight both old fans and those who are just making the Muppets’ acquaintance.