Shrek the Third

The cast of characters continues to expand in “Shrek the Third,” the latest rowdy adventure in the ever-amusing fairy-tale-spoof series. A petulant young King Arthur and a baffled old Merlin are among the new arrivals, while princesses such as Snow White and Rapunzel — previously referred to but not given much screen time — get a chance to demonstrate their unique skill sets. (We knew Snow White could summon birds with her voice. Who knew she could make them attack by singing Led Zeppelin’s “Immigrant Song”?)

This outing looks toward the next generation, as Far Far Away’s King Harold (John Cleese) is dying, and he’s named Shrek (Mike Myers) as his heir. The ogre doesn’t want the gig, though, and defers to Plan B: a royal nephew named Arthur (Justin Timberlake) who is presently a gawky teenager who gets picked on even by the Dungeons & Dragons geeks. (Shouldn’t there be a joke about playing Dungeons & Dragons at a time when there really ARE dungeons and dragons?) Artie doesn’t want the job either, once he learns how hard it is, so Shrek has to persuade him, lest he be saddled with it himself.

Meanwhile, Shrek’s beloved wife Fiona (Cameron Diaz) is pregnant, sending more ripples of panic into Shrek’s green heart. Ogres aren’t known for their nurturing, fatherly attributes, after all. Sure, Donkey (Eddie Murphy) and the dragon have spawned a litter of happy, if horrifyingly freakish, donkey-dragon hybrids. But is there any hope for a pair of swamp-dwelling ogres?

Meanwhile (there is a lot of meanwhile in this movie), Prince Charming (Rupert Everett) is enduring nightly humiliation playing himself in a bad dinner theater play. Determined to seize the throne once and for all, he rallies all the other fictional losers — Captain Hook, Snow White’s wicked queen, various witches, and so forth — and stages a coup while Shrek, Donkey, and Puss-in-Boots (Antonio Banderas) are off looking for Arthur. Fiona, Queen Lillian (Julie Andrews), and their bickering princess girlfriends are tossed into prison.

One of the few film franchises to retain a high level of quality even on the third outing, “Shrek the Third” is loaded as ever with anachronism-based jokes, raucous parodies, and good old-fashioned silliness. It’s fast becoming a “Simpsons”-like universe, where any member of the huge cast of characters can get a laugh just by delivering one line. Puss-in-Boots, the great discovery in “Shrek 2,” is used (but not overused!) to great effect here, and the Gingerbread Man (Conrad Vernon) has some of the film’s funniest non-sequitur moments. (You have not truly lived until you have seen a Gingerbread Man’s life flash before his eyes.) Likewise, there are winning cameos from the Three Pigs, Pinocchio, the apple-throwing “Wizard of Oz” trees, and a host of other familiar characters.

That said, it could be that the film (directed by regular “Shrek” contributors Chris Miller and Raman Hui, and written by a gaggle of scribes) emphasizes the auxiliary characters at the expense of the central ones. Fiona, for example, feels like a non-entity in this chapter. That’s a shame, considering her relationship with Shrek was the central element of the first two films.

Furthermore, several of the movie’s funniest elements — such as Arthur’s high school, where teens talk in a mix of King James English and modern slang, and the gaggle of diva-like princesses (voiced by various “SNL” alum, plus Amy Sedaris) — are gone before they’ve fully lived up to their comedic potential. And why go to the trouble of hiring Ian McShane (the terrifying villain on HBO’s “Deadwood”) to play Captain Hook if you’re only going to give him a few lines?

On the whole, there’s not nearly as much depth of emotion here as there was in the previous installments. Shrek is supposed to be the giant monster with a soft heart, and while he’s as lovable as ever, here the “tender” moments — as when he mentors young Arthur — feel obligatory. Which is a fancy way of saying the movie focuses more on laughs than on feelings, which probably won’t register as a very serious complaint.

Nor should it, really. It means the film doesn’t resonate as a classic, that’s all. For giddy, rude, daffy humor, it works just fine. Because really, once you’ve seen a chorus of frogs singing Paul McCartney’s “Live and Let Die” at the funeral for their king, whose body is in a shoebox floating away on a lily pad, what else do you need?

B+ (1 hr., 33 min.; PG, some crude humor, some mildly suggestive references.)