Who needs movie superheroes like Iron Man when audiences can rely on a panda named Po with a sick kung fu kick? Not Dustin Hoffman, Angelina Jolie, Jack Black or any of the stars of Kung Fu Panda.

The computerised movie from DreamWorks Animation, the studio that gave audiences the hit Shrek films, stole the media spotlight at the Cannes film festival on Thursday with a message that anyone can be a hero if they believe they can.

"The superhero is only there in culture because people feel a deficiency inside them," Hoffman told reporters at a news conference. "You don't need a superhero. The superhero is inside you."

In a summer movie season where Iron Man already is nearing $US200 million ($A214.48 million) at US and Canadian box offices, and other comic book characters like Batman and the Incredible Hulk are due to hit theatres in coming weeks, it's obvious that moviegoers love their superheroes.

But animated movie Kung Fu Panda, which debuts around the world starting in June, is an unconventional screen idol built more for laughs than for beating up the bad guys.

Po (voiced by Black) is fat, lazy and serves noodles at his dad's cafe. Yet he dreams of being like the kung fu fighters taught by Master Shifu (Hoffman).

When Po is mistaken for a mighty warrior who will save the valley in which he and all his animal friends live, he must learn to be the tough-minded panda of his wild imagination.

But Po is far better at eating than fighting - unless he has food for motivation. Then, he is quite tough.

"I think of myself as kind of a bear. I'm very furry and soft and squishy and lazy, and sometimes fierce and crazy. There was little acting involved. I am Po; Po is I," said Black - no svelte movie star himself.

"It is some of the best work I've done," he added.

Jolie, who voices a fighter called Tigress, said Kung Fu Panda with its theme of discovering one's true self inside and out, is perfect for kids.

She said three of her growing pack of children - she is pregnant with twins - have already seen and liked the animated film. "And they are my biggest critics," Jolie said with a smile.