Answer to the "19,000 Prompts, 500 Words, One Week" Challenge.
Black Hound
The image of the grim had decorated the Black Coat of Arms for centuries. At first glance people assumed the black dogs flanking the shield to be common dogs, but those who knew about the history of the old family knew better.
Why it was the Grim was not known outside of the house however. It had to do with Black Magic, the darkest of the Dark Magics that had first given the Black family their name, a form of magic that to this day only the descendants of the Black family, touched by the family magic were capable of. It had to do with one Witch binding a grim and forcing him into human form. The rest is history.