We are into the Twelve Days of Christmas (the Twelvetide), that period between Christmas Day and the Twelfth Night before Epiphany. For most people worldwide, it’s a time of feasting and merriment as we celebrate the Nativity. But for the people of Greece, it is also a time to beware… goblins!

I learned about the Kallikantzaroi (singular: Kallikantzaros) while researching my new novel Aphrodite’s Tears, which required digging deep into legends and mythology associated with Greece through the ages. There are all sorts of old stories about these ugly creatures in Greece – and also further afield in Serbia, Turkey and Bulgaria.

Descriptions of the Kallikantzaroi vary from the fairly benign to the downright gruesome. At their best, they are ‘beautiful centaurs’ (the translation of the Greek word). At their worst, they are small, dark creatures with a human aspect but animal parts – rat tails or donkey ears or monkey arms or boar tusks. Their eyes burn with a devilish fire, but they don’t see well. They smell terrible, no doubt in part due to their diet: insects and frogs. They are mischievous and impish, like Irish leprechauns.

Legend has it that the Kallikantzaroi dwell underground, busily sawing away at the Tree of Life, but during the Twelve Days of Christmas they forget their task because a route opens to the surface. Up they swarm and into people’s homes (via their chimneys) to wreak havoc.

Whatever goes wrong during this 12-day period, you can blame it on these goblins. Milk gone off? Blame the Kallikantzaroi. Fire gone out? That will be the Kallikantzaroi. All of your Christmas food eaten? A whole pack of Kallikantzaroi descended on you!

So how can a Greek family protect themselves from these troublesome visitors? Here are some old traditions:

* Keep a fire burning at all times in the fireplace to block the Kallikantzaroi’s entry. An optional extra: throw old, smelly shoes and salt onto the fire to repel them.

* Hang food offerings inside the chimney – sweets or meat.

* Paint a black ‘no goblins welcome’ cross on your front door.

* Sprinkle holy water around each room of house once a day. (It is customary in Greece to put out a wooden bowl over the Christmas period, over which is hung a cross wrapped in basil.)

* Best of all, leave out a colander to distract any Kallikantzaros who makes it past your defences. Apparently, Kallikantzaroi are so stupid that they cannot count higher than two, and their attempt to count all the holes in the colander will keep them out of mischief until morning. (According to some sources, if they manage to count to three – the holy number – they will combust.)

Come morning, you are granted a reprieve from worrying about the Kallikantzaroi: like so many magical creatures, they only come out at night (and burn up in sunlight like vampires).

You may in fact be more worried about turning into one yourself. According to legend, if you were born during the Twelve Days of Christmas then you could transform into one of these goblins, unless your parents took preventative measures: binding you in garlic and straw, or (I can barely stand to write it) dangling you over a fire until your toenails blackened!

The stories of the Kallikantzaroi are colourful indeed, but with a dark undercurrent – as is so often the case with folklore. I loved stories like this, told by my governess, when I was a child; but how they frightened me as well. I think, had I grown up in Greece, I would certainly have wanted the fire left burning all day and night. In fact, it’s tempting to do so even now – and surely it wouldn’t hurt to leave out the colander, just in case…