A Brownie is a Light Fae who enjoys cleaning and doing other household chores, asking only to be appreciated.
Kenzi hired a Brownie named Mumphert to do the housework in return for providing him with all the cereal (Honey Berry Crunch) to eat that he wanted.
An unappreciated brownie becomes vindictive. The 'employer's' gratitude needs to be shown by stocking honey and similar delectables for the Brownie, who will seemingly happily shop for almost anything else.
A brownie/brounie or urisk (Lowland Scots) or brùnaidh, ùruisg, or gruagach (Scottish Gaelic) is a legendary creature popular in folklore around Scotland and England (especially the north, though more commonly hobs have this role). It is the Scottish and Northern English counterpart of the Scandinavian tomte, the Slavic domovoi and the German Heinzelmännchen.