SFX are nice enough to give away their Paranormal Special's article on the subject.
Nessie, the Great Grey Man of Ben MacDhui, the Lambton Worm... Ten in all, enough to fill a British supernatural adventure show, turn out to be aliens in a series' worth of Doctor Who or cryptids in Primeval, inspire fantasy beasts or horror monsters and more.
Are the Owlmen the Strix from Vampire: The Requiem in their natural form? Is the story of the last Cottingley Fairy picture being real the truth? Is the Black Dog a friend or an enemy?