Grim

From UnknowableWiki

A Grim is a legendary magical creature that is considered a death omen in Divination. It is a huge spectral black dog with gleaming eyes that haunts churchyards (PA4, PA6). Superstition holds that those who see a Grim will die shortly (PA6).

The picture of a Grim adorns the cover of Death Omens: What to Do When You Know the Worst Is Coming. Harry Potter sees an edition at Flourish and Blotts in August 1993 and feels reminded of the black dog he saw in Little Whinging before he was nearly run over by the Knight Bus (PA4). The dog was in fact Sirius Black in his Animagus form (PA17).

During the third-years' first Divination class, Sybill Trelawney claims that Harry's tea-leaves show a Grim and that he is doomed to die. Hermione contradicts her and says that the tea-leaves do not look like a Grim to her. Ron later asks Harry whether he has ever seen a great black dog lately. Harry admits that he has, and Ron is shocked. Hermione calmly remarks that it was probably only a stray, but Ron insists that the situation is serious. He claims that his uncle Bilius died twenty-four hours after seeing a Grim. Hermione simply states that this was either a coincidence or that the fear most wizards have of Grims causes them to die (PA6).

Harry sees Sirius as a dog again during the Quidditch match against Hufflepuff. Shortly afterwards, he falls from his broom because Dementors enter the stadium (PA9). Harry worries because he has now seen what he thinks is a Grim twice, both times followed by nearly fatal accidents (PA10).

Hermione finally loses patience with Trelawney when the latter claims to see a Grim in Harry's crystal ball. She quits Divination. Harry sees Crookshanks and Sirius prowling the Hogwarts grounds together the night before the final Quidditch match and wonders whether the dog can be a Grim if Crookshanks can see it, too (PA15).