Kallikantzaros
The kallikantzaros (Greek: καλικάντζαρος, romanized: kalikántzaros) is a malevolent creature in modern Greek folklore. Kallikantzaroi are believed to dwell underground spending most of the time trying to saw down the giant tree that supports the earth, but come to the surface during the twelve days of Christmas, from 25 December to 6 January (to Theophany/Epiphany).