The legends surrounding Black Shuck- the Devil's Dog said to stalk the English countryside, habitually terrifying the unwary- stretch back so far that they predate the Vikings. With flaming eyes as big as saucers, the scary spectral canine was the basis for Arthur Conan Doyle's The Hound of the Baskervilles (also a Hammer Production, don't you know?).
A water-dwelling bogeyman, usually green in colour, with long sinewy arms and a penchant for drowning little children, Grindylows are also known to be a pain in the hump for Triwizard Champions.
A particularly ghastly demon from Ordadian mythology, the Nuckelavee is part rotten horse, part devilish man. Considered to be the most evil of all the Scottish folkloric creatures, the Nuckelavee's breath is said to wilt crops and sicken livestock, and the creature's presence was held responsible for droughts and epidemics on land (though the beast was predominantly sea-dwelling).
4. Bean Nighe
The Highland iteration of the ominous 'Washerwoman of the Ford', the Bean Nighe is a lady you most certainly don't want to find cleaning your smalls.
Appearing to most witnesses as an old hag complete with webbed feet, one nostril and one tooth (though she was also known to adopt the image of a beautiful young woman), the Bean Nighe was said to be found at the sides of quiet streams and pools washing blood-stained clothes. This was a terrible omen for whoever the clothes belonged to as it meant that they were going to die soon after.
If one was careful and daring enough when approaching, and managed to come between the Bean Nighe and the water, they were able to ask three questions which the supernatural washerwoman had to answer truthfully, but only once the person answered three questions themselves. Would you take the risk?
5. Cù Sìth
A sighting of the Cù-Sìth brought a similar sense of foreboding as the Bean Nighe - a giant dark green wolf which roamed the Scottish mountainside, the beast was believed to be a messenger of death.
6. Black Annis
In a grim, remote Leicestershire cave hewn with her own scraping, steel-clawed hands, the old crone Black Annis was said to hang the trophy skins of flayed children. A terrifying, lonely creature which lived in the branches of a gnarled great oak- the lone remnant of a long-dead great forest- Black Annis was thought to have been the husk of a forgotten dark Pagan Goddess.
Now if that isn't the nightmare-fuel for kids, we don't know what is.
Yet another omen of impending death, the Irish Fetch is a kind of doppelgänger which assumes the identity of someone about to die. Its name is believed to refer to the "fetch-life", a psychopomp sent to fetch the souls of the dying. So if you see one, probably wise to start composing a "goodbye" group text fast...
8. Loch Ness Monster
Though mentions of Nessie date back to the abbot Adomnán's 7th century text Life of St. Columba, it wasn't until the early 1930s- when photographs taken by Hugh Gray and Robert Kenneth Wilson surfaced- that the modern legend of the monster took hold with the public. Numerous sightings have since been reported, and in 1954 a mysterious sonar contact was recorded by the fishing boat Rival III. Neither the nature of the beast, nor confirmation of its existence, are known, but this hasn't prevented the legend of Nessie continuing to grow.