According to Greek folklore, supernatural beings with unusual powers are present upon earth during the 12 days between Christmas Eve and Epiphany. The name for these spirits is kallikantzari, and they wander about during the Christmas season causing mischief. They are ugly and unkempt, and their favorite way of getting into the house is through the chimney, much like the traditional Santa Claus. Christmas masqueraders often dress in animal skins to represent these demons, and their jangling bells are supposed to drive the spirits away. Discuss
Source: The Free Dictionary