Brownies are cousins to the leprechaun. Brownies, as a rule, are very benign. Any household that is blessed by the presence of a brownie can count on many of their chores being done for them at night secretively. If the household is, in turn, kind to the brownie by leaving food for him every night. The brownie will continue to live with that family.
Brownies are extremely secretive. They like to be alone. If a family stays up at night to look for the brownie, the brownie will leave and find a new place to live. Also, if a family brags that they have a brownie, the brownie will feel betrayed and leave. If a brownie stays with a family for a long amount of time, a bond will develop between the brownie and the family. If that family is ever attacked by any outside force, the brownie will help.
Brownies will usually have between 3 and 5 levels of magic. Most of the spells that they know will be of the useful nature, but several will be offensive and defensive.
Reality
(1505-1515) Scottish
Brownies are elves that will help with chores at night. Usually, if a farmer leaves a bowl of cream and some bread, the brownie will stay on and help that family indefinitely.