Knockers
Knocker means “knocker” or “one who knocks”; it is a kind of elf or goblin that takes its name from its great skill in handling the pickaxe and hammer while working in the galleries of abandoned mines. Knockers wear an outfit consisting of leather aprons and carry a pickaxe on their backs.
It is said that when someone hears the hammer of one of these goblins, it is an omen of good luck, as the person will have the chance to find gold or precious stones. But if the hammering inside a mine is too loud, the right thing to do is to flee, as it may be a warning of an imminent collapse. Those who believe that a knocker has brought them fortune must feed it frequently and generously, offering it a tray of food, either in the mines it inhabits or in a corner of the beneficiary’s home.