In a strange village that's built on a mountain and where the inhabitants eat lots of cheese, an infant boy is taken by a Boxtroll named "Fish". These strange inventive beings live underground in a huge cavern and go to the surface to forage for scraps. Years go by and the boy, named Eggs, believes he's one of them. But sinister Archibald Snatcher (voice of Ben Kingsley), a creepy man in a red hat, spreads the news that the trolls are dangerous. He sets up an extermination business and begins to capture them all. Eventually Eggs learns that he's really a human--and the truth of why the BoxTrolls had taken him, which of course has to do with Snatcher.
Visually, this movie is amazing, up there with a Tim Burton produced animated film. The Boxtrolls is extremely entertaining and highly recommended.