Nisse

The nisse is a small, usually bearded, humanoid. They wear conical hats in red and other bright colors. They live on farms and help out and care for the animals. Despite their size, they have super human strength and can be quite mean spirited if proper respects aren't paid. If food is left out for them, they will help generally be helpful, but will otherwise cause a variety of problems for the farmers, ranging from minor pranks, to the killing of livestock. In modern times however, they are mostly connected to christmas where they serve as the helpers of Santa Claus.

Source
The nisse is featured in scandinavian folklore.

Media
The nisse appear in the following media: