You should start the book by introducing Santa Claus, Krampus and the relationship between the two. Below is an example:
Christmas is a magical time that we all look forward to. Like any magical event, Christmas has its legends and mythological creatures that populate our imagination and even interfere with our Christmas traditions. The most famous mythological creature in this case is Santa Claus, a good old man who gives gifts to children who have behaved well during the year that is ending. However, you may ask yourself "what about children who misbehave?" Well, my friends, these children are also visited by a mythological Christmas creature, but it is not Santa Claus but Krampus, who is a demonic show that punishes children who did not show good behavior.
