The sound of the chain would frighten people so much that they would stop in their tracks only to be caught by the dog. The dog would then circle its victim at great speed in order to terrify them further.

No bodily harm was ever done to the victims but they were usually found cowering against a hedge in a state of shock after their encounter with the Black Dog. Due to this, the slightest mention that the dog had been heard was enough to send people hurrying back to their homes.

But did the dog ever exist, or did smugglers make him up, so that scared parishioners wouldn't see them landing secret stores of brandy and tobacco?

It is still said that if you do see Le Chien de Bouley, there will be a storm.