Growing up, this and the other books in the World of the Unknown (one volume of UFOs and another on werewolves and vampires) were some of my favourites. It was probably one of the books that most warped me as a kid, and there were images in them that I couldn't look at for fear of nightmares. Blood and violence, strange chills up and down my spine.
The one story that stayed with me was the one of Gef the Mongoose. On the Isle of Man in the 1930s a farm was haunted by a talking mongoose who claimed to be the reincarnation of a man from India.
There was an ambiguity in the nature of Gef that stuck with me. He showed concern for the family, while at the same time threatening them with murder. There was also debate over if Gef was a poltergeist or a criptid (talking animal) or if he were the creation of the young girl of the family, Voirrey.
And in thinking about what to write, this was the story that crept to the front with it's claws in a crack in the ceiling.