Stitch, a pearly-toothed extraterrestrial gremlin, splashes down in Hawaii, and he certainly looks colorful; he's like a demonic koala bear crossed with Pikachu from ''Pokemon.'' The moment, however, that he springs into action, speaking in what sounds like angry samurai gibberish, it's clear that he has zero dimensions as a character. (He would have been stuck somewhere in the back of a closet in the ''Toy Story'' films.) Stitch gets discovered by Lilo, a temperamental Hawaiian girl who's the whiniest of whiny brats. The animation in Lilo & Stitch has an engaging retro-simple vivacity, and it's nice to see a movie for tots make use of Elvis Presley, but the story is witless and oddly defanged.