PG? Really?
I almost didn't take my 3-year-old to see this because it was rated PG. I'm glad I ignored the rating, because the film was wonderful, and the rating is completely unwarranted. There are a few mildly scary scenes. As far as I can tell, the rating is mostly because someone smokes a pipe at one point (I don't even remember when) and there's a sign that says "FEIC OFF! NO HUMANS." Big whoop, MPAA.
Long story short, go ahead and take your small children to see it.