How to Train Your Dragon, the new 3-D digital fable from DreamWorks Animation, has a kinetically dreamy, soaring-through-the-air effervescence. On some level, though, it's just the sweetly simple tale of a boy and his dog. The boy, Hiccup (Jay Baruchel), is the son of a toweringly gruff, red-bearded Viking named Stoick (Gerard Butler, in his teeth-gnashing element). The ''dog'' that Hiccup befriends is a fearsome dragon a Night Fury, who in the film's fire-breather cosmology (there are a dozen breeds, each with its own funky look) bears the distinction of being so fast that it can be glimpsed only as a purplish streak against the night sky. No wonder the Vikings live in mortal fear of them.
Dragon slaying is the clan's primary career option, although Hiccup wants nothing to do with it. He's like an adolescent indie rocker who's been born into a village of rampaging middle linebackers. One night, while wielding a catapult slingshot, he ham-handedly slices off half a dragon's tail (which grounds it from flying), and then stumbles onto the creature nursing its wounds at a woodland crater lake. The place is visualized with an almost classical deep-focus fairy-tale beauty, and the dragon itself looks like a jet-black Gila monster with wings. The connection that develops between the two is no cloying, smiley-happy animal-human friendship. It's more like the stirring bond you remember from Old Yeller, with an added touch of King Kong.
At times, How to Train Your Dragon is like a Harry Potter film with less clutter. It has winningly Potteresque teen-dragon-slayer classes, a queen-bee dragon as grand as Godzilla, and a layer of age-of-terror allegory about the ignorance bred by jingoism. The Night Fury, named Toothless, is a voracious yet inwardly serene beastie whose trust must be won, which Hiccup does by feeding him slimy fish, building him an artificial tail, and saddling him up. How to Train Your Dragon rouses you in conventional ways, but it's also the rare animated film that uses 3-D for its breathtaking spatial and emotional possibilities. When Hiccup and Toothless take to the sky, we're free of constraint, aware of the space on all sides. At moments like those, the movie makes you feel in every way miles high. A-