There were many traps for the unwary in old Japan. You could be out walking at twilight at the edge of town and meet a beautiful woman. But before you proposed marriage, it would be as well to check whether she had a bushy tail protruding from her skirts. Otherwise you might wake up and discover that you’d slept with a fox.

Or you might buy a cooking pot that screamed when you put it on the fire and revealed itself to be a tanuki (Japanese raccoon dog), badly burnt and probably dead. (Tanuki are rather inept shape changers, unlike foxes.) On 3 May 1889 a train driver reported a train steaming straight towards him that suddenly disappeared, leaving a dead tanuki on the track. Domestic utensils like pots and pans had a tendency to grow arms and legs, and cats might develop a split tail and turn into cat monsters.

The catch-all term for these ghosts, demons, sprites, goblins and monsters, old and new, is yōkai. But they are not just quaint folkloric creatures. There are also modern ghouls, such as the woman who has a mouth that slits her face from ear to ear, who scared schoolchildren and reportedly