This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Black Shuck – (Norfolk, Essex, and Suffolk)
In English folklore, Black Shuck, Old Shuck, Old Shock or simply Shuck is the name given to a ghostly black dog which is said to roam the coastline and countryside of East Anglia, one of many such black dogs recorded in folklore across the British Isles. Accounts of Black Shuck form part of the folklore of Norfolk, Suffolk, the Cambridgeshire Fens and Essex, and descriptions of the creature's appearance and nature vary considerably.
It is sometimes recorded as an omen of death, but, in other instances, is described as companionable. Descriptions of Black Shuck vary in both shape and size, from that of a large dog to being the size of a calf or horse. He takes the form of a huge black dog, and prowls along dark lanes and lonesome field footpaths, where, although his howling makes the hearer's blood run cold, his footfalls make no sound. You may know him at once, should you see him, by his fiery eye; he has but one.