One dark, misty night at Mossy Bottom Farm, a starving creature creeps silently through the farmyard, waiting to feed. Well, actually, it's just Bitzer the sheepdog with a growling stomach, holding his clipboard as he checks on the flock and chickens. But wait – what's that howl that's making his fur stand on end? Is it Shaun the sheep playing one of his pranks? The farmer practising his trombone? Suddenly the moon appears, and there it is: a hulking shadow on the side of the barn that must be the outline of a ... beast! Are they all doomed, or can Bitzer and Shaun concoct a madcap plan that's so crazy it just might work?