The Giant Mountains has a legendary spirit named Rubezahl. There are many
tales about how he would help deserving people and make life difficult for
those who were selfish, greedy or lazy. He would help needy children by giving
them a magic key to a cupboard that was always full of good bread and cheese
and milk -- but never cake. His method seemed to be to give people what they
needed to thrive on their own but woe to anyone who did not follow the rules
he laid down when he said he would help them.
Rubezahl is still a favorite of many German children. He is a sort of Bogey
Man and a benevolent spirit at the same time.
There are some short tales of Rubezahl in the book at the GBHS website, "One
Hundred Tales from Sudetenland." The tales are separated according to the
parts of Bohemia where they were popular. For example, along the Eger river
there are stories of water spirits but in the mountains they are stories of
Rubezahl (who lives underground) and miners.