Justin Timberlake (Left) and Anna Kendrick at Cannes on Wednesday Photo: IC

The world is about to be overrun by millions of grinning pink and blue plastic dolls whose hair stands on end.

That is at least what DreamWorks boss Jeffrey Katzenberg was hoping for Wednesday as he gave the first sneak preview of Trolls at the Cannes film festival, in what he hopes will be his studio's next animated children's blockbuster.

After the screening, fans and even some grown journalists screamed with pleasure as pop star turned actor Justin Timberlake and singer Anna Kendrick appeared on stage to sing "True Colors" from the soundtrack.

The pair voice the 3D film's two main characters, the ever-smiling Princess Poppy and the lugubrious Branch, the odd couple who have to save the miniature dolls from the terrible troll-eating Bergens.

Speaking to reporters, Katzenberg said that thanks to Timberlake, who is also the film's executive musical producer, "music plays a bigger role in this film than any DreamWorks film before."

The singer has also written and sung some tracks for the movie, which is to be released in November.

Its directors Mike Mitchell and Walt Dohren are part of the team behind DreamWorks' massively-successful Shrek movies, and Katzenberg said they had brought much of its tongue-in-cheek humor to the film.

"You will notice little moments of irreverence and subversiveness," he said as he introduced a clip in which one particularly frightened troll poos cupcakes.

Mitchell joked that their "familiarity with ogres led us to their not-so-distant cousins, trolls. We are fascinated by how the trolls, these scary ugly creatures have evolved into lovely happy creatures".

The story opens in "Troll Village where everyone is perpetually happy," Mitchell said. "Trolls spend most of their waking hours singing, dancing and hugging. Trolls even wear 'Hug Time' watches to remind them to hug every hour on the hour."

But this idyll is shattered when the Bergens, "the most miserable creatures in the world," attack, and some of Poppy's best friends are troll-napped.

"There is only one thing that makes the Bergens happy, that is eating a troll," Dohren added. So Poppy must persuade the only troll tough enough to take on the Bergens to help her - the "ever-prepared, overcautious Branch", who is voiced by Timberlake.