In Greek folklore, these are demonic creatures, dark in colour, with long tails and ears, sharp pointed teeth and red eyes.
They usually live beneath the earth where they spend their time trying to saw through the trunk of the tree holding up the earth. At Christmas, lured by cooking smells, they come up to the surface. According to legend, at night they clamber on to the roofs of houses trying to enter them via the chimney in order to steal food.
In some parts of Greece, housewives cook special fritters and throw some on to the roof or leave them outside so that the kalikantzari will find them and not attempt to enter the houses in search of them.
They return to their lair beneath the earth on Epiphany (6th January) when, traditionally, Greek priests bless homes and the sea. On their return, they find that, in their absence, the tree trunk has grown back fully and they have to start the process of cutting it all over again.