Pwca

A goblinlike fey creature born from the centre of an ancient tree stump, Pwca is a being of nature and all of its incomprehensible whims. Capricious at best and tempestuous at worst, it's as likely to hurt you as it is to help you, but any who find Pwca as a guardian will be well protected from hostile fey. It possesses a deal of magic and the power to manipulate your luck at will, whether for better or worse.

If you leave a bowl of milk and honey on your windowsill, you might be paid a visit...