The penguins are as adorable as ever in “Happy Feet Two.” Yet a couple of shrimp-like krill at the bottom of the food chain almost steal the show in this animated sequel that sticks to the

formula of the original while adding enough variety to give it a life of its own.

It helps to have Brad Pitt and Matt Damon voicing the krill with great energy and companionability as they join a vocal cast that includes returning stars Elijah Wood and Robin Williams.

Director and co-writer George Miller, who handled the same chores on the 2006 Academy Award-winning first film, keeps the focus on penguins in peril while adding an interesting nature-in-perspective angle with the side journey of those tiny krill trying to find their place in a world of bigger, hungrier things.

The sequel delivers the key ingredients that made its predecessor such a hit: lovable characters that audiences young and old will want to follow. A rich blend of pop tunes employed in show-stopping song-and-dance numbers. Remarkable photo-realistic Antarctic landscapes whose bleak beauty pops off the screen even more than in the original, thanks to some of the finest use of 3-D animation since the digital age brought an extra dimension to the screen.

The snowy crags and peaks seemed tactile in “Happy Feet.” In “Happy Feet Two,” you feel you could reach up and touch them, while the deep blue skies, with their billowy clouds, look real and right outside the window, rather than computer creations projected on a movie screen.

With co-stars Nicole Kidman and Hugh Jackman out of the picture, “Happy Feet Two” is a next-generation story that follows the misfits-finding-their-place pattern of part one.

Once a freak for his tap-dancing skills in a colony where singing was the supreme talent, emperor penguin Mumble (Wood) is part of the establishment now that hoofing has joined crooning as a prized gift.

Mumble and his mate, Gloria (pop star Pink, subbing for the late Brittany Murphy, who voiced the character in the original) have a tyke of their own, whose identity issues seem too pat a repetition of those his dad once faced.

Young Erik (adorably voiced by Ava Acres) hasn’t got rhythm, you see, an embarrassment for the son of the local lord of the dance. Running away with a couple of friends as they chase after Mumble’s buddy Ramon (Williams) on the return to his own penguin colony, Erik meets the amazing “flying penguin” Sven (Hank Azaria), whose can-do attitude makes him the idol of the youngster, to Mumble’s detriment.

Miller again shovels on an eco message as a colossal iceberg cast adrift by climate change endangers the entire colony of emperor penguins. Once the crisis arrives, the action bogs down a bit, the movie lingering a long while on its penguins-on-the-precipice menace without a whole lot happening.

But with its interspecies collaboration, as birds, elephant seals and even the little krill contribute to a happy ending, the movie is a stirring, if kind of sappy, endorsement for the good that can result when everyone rows together.

The best addition of “Happy Feet Two” are Pitt’s Will the Krill and Damon’s Bill the Krill, who are so engaging they deserve their own buddy-comedy spinoff.

When Will decides to swim out on his own to see the world beyond the teaming krill swarm, skittish Bill tags along. They discover to their horror that krill are just munchies for other aquatic life, sending Will on a comic quest to move up the food chain and become a predator himself.

The krill interludes are delightful, and the dark, quiet depths through which they swim make a lovely contrast to the bright world of the penguins above.

The camaraderie of Pitt and Damon, co-stars in the “Ocean’s Eleven” movies, comes through loudly in their goofy banter, making them highlights of an already stellar voice cast.

Williams again does double duty in two breathlessly manic roles, voicing both Ramon and Lovelace, the colorful penguin who becomes a key disciple of Sven. Azaria, one of the vocal masters behind “The Simpsons,” extends his reputation as one of Hollywood’s top voice stars, giving Sven a gurgling Scandinavian accent that’s an absolute hoot.

Pink belts out pop songs old and new, co-writing one number, too. Williams, Azaria, co-star Common and even Pitt and Damon get in on the singing, the tunes woven cleverly into the themes and action.

You have to applaud a group of filmmakers that can take millions of disparate creatures — plus songs as different as Queen and David Bowie’s “Under Pressure” and the theme from “Rawhide” — and unite them in a rousing, harmonic climax where for one brief Hollywood moment, predators and prey have a common cause.

“Happy Feet Two,” a Warner Bros. release, is rated PG for some rude humor and mild peril. Running time: 99 minutes. Three stars out of four.