Black Shuck is a legendary black ghost dog that wanders the coastline and countryside in East Anglia in England.
It is classified as cryptid, a demon, and a harbinger of death. The dog's eyes are reported as red and sometimes even green, large, and mesmerizing. Some report him as being the size of a large dog, others the size of a horse.
The legend might go back as far as the time of the Vikings and the name translated to "hairy demon." In fact, the story even influenced the Sherlock Holmes novel,"Hounds of the Baskervilles."
Frequently it's been reported to be seen by someone just before a relative fell ill or died. Other tales say that he has escorted lone women safely home. He is most often reported in graveyards, side roads, near bodies of water and forests.
From this site, "One of the most notable reports of Black Shuck is of his appearance at the churches of Bungay and Blythburgh in Suffolk. On 4 August 1577, at Blythburgh, Black Shuck is said to have burst in through the church doors. He ran up the nave, past a large congregation, killing a man and boy and causing the church tower to collapse through the roof. As the dog left, he left scorch marks on the north door which can be seen at the church to this day."
A report in 1972 at a beach described, "I saw a large black hound type dog on the beach, about a quarter of a mile north of the lookout. What made me look was that the dog was running then stopping, as if looking for someone. I watched it for one or two minutes and then it vanished before my eyes. I kept on looking for a time but it did not reappear.”
Reports have diminished over the years and more and more UK residents are reporting large black cats. Some legends are forgotten over time. There might have been residents who saw black dogs and thought of them as nothing but black dogs, not realizing the legend existed.