“Shrek the Third” begins with a death, and from there the movie itself steadily dies.

The third installment in this monster of an animated franchise still subverts the fairy tales we grew up knowing and loving, but it’s smothered in a suffocating sense of been-there, done-that.

Thankfully, as the films go along, they rely less on gratuitous pop-culture references. And visually this “Shrek” is more dazzling than ever, especially in the realistic background details. The water looks watery and the sand looks sandy and the trees look so lush and leafy you could practically jump out of your seat and climb into one of them. By now it’s probably easy for all of us to take for granted how far CGI technology has come, and it’s worth stopping to appreciate for a moment.

But part three also lacks the zip of its predecessors; it feels draggy and, at the same time, rushed. (At 86 minutes, it’s also the shortest film in the series.) Except for a few moments here and there, such as Prince Charming’s gleefully corny stage productions and a Gingerbread Man flashback montage, much of the original sense of ingenious fun is gone.

It doesn’t help that so many tired “Shrek” wannabes, like “Hoodwinked” and “Happily N’Ever After,” have been trotted out in recent years, making the real thing feel just as hackneyed. Chris Miller, previously a story artist, co-directed with animator Raman Hui. About a half-dozen people are credited as having contributed to the script, including Andrew Adamson, who directed the first two “Shrek” flicks. So there is a sense of consistency – it just doesn’t feel all that fresh anymore.

This time, the lovably cranky ogre Shrek (voiced reliably as always by Mike Myers) struggles with the prospect of becoming king of Far, Far Away after the death of King Harold, the father of his bride, Fiona (Cameron Diaz). He’d rather stay home in the swamp, lazing around all day.

(Why Fiona can’t take over in a fairy-tale land where the all the other rules have been upended is never addressed. She is the more even-tempered and levelheaded of the two, after all. Perhaps if Hillary were president ….)

Anyway, Shrek sets out with his chatty sidekick Donkey (Eddie Murphy) and the suave Puss in Boots (Antonio Banderas, still an adorable scene-stealer) to find the only other possible heir to the throne: the nerdy, insecure Artie, Fiona’s teenage cousin, who is voiced by Justin Timberlake and looks like Corey Feldman.

Artie is always on the receiving end of Lancelot’s athletic jousts and is otherwise the butt of everyone’s jokes at his medieval high school – the irony being, of course, that Timberlake has long been the coolest kid in the class. So when Shrek and his pals show up and offer him the kingdom, he’s only to happy to take it. At first.

Meanwhile, with hubby away, Fiona is left to defend the castle from Prince Charming (Rupert Everett), the vain former suitor she once jilted who has now come back to stage a bloody coup with a posse of vanquished villains (Captain Hook, the Evil Queen, etc.).

Fiona – who’s pregnant with the baby Shrek isn’t sure he’s ready for – gets some unexpected help on her end from longtime damsels in distress Snow White (Amy Poehler), Cinderella (Amy Sedaris), Rapunzel (Maya Rudolph) and Sleeping Beauty (Cheri Oteri), as well as her mother, Queen Lillian (Julie Andrews).

It’s a clever idea to have these characters transcend their stereotypes, but with the exception of Poehler’s demanding diva, they all feel tossed in and underused. Like “Spider-Man 3,” “Shrek the Third” throws more at us – including plenty of barf and flatulence jokes for the kids – but too little of it actually sticks.