Have you heard of the Grim or Church Grim? A large black dog that haunts church yards and said to guard the dead, though it is featured in Harry Potter and the Prisoner of Azkaban as an omen of certain death, which of course, Harry keeps seeing throughout the year.Remember the story of the truckers who see the Black Dog? They say if they see the Black Dog, they will soon have a serious accident or get killed. I have also heard a bunch of other dog stories.