But Stitch turns out to be an alien programmed to destroy things! And he's being hunted by evil scientists who want to experiment on him.
The film, which was released on 3 October, beat other big adult flicks to number one at the box office, like sci-fi thriller Signs, which it actually knocked off the top.
It didn't do as well in the US when it came out. But it's still made an out-of-this-world £134m ($210m) around the world.