I was just spit balling ideas because I didn't have time to do an actual investigation. Now that I have I still don't know what we should do with them as a creature, but I will share the important parts to see what people think we should do. I'm also going off the original ancient Swedish beliefs because they are way cooler than the modern ones that make them out to basically be gnomes. So, it's said that they represent ancestors and are no more than 35 inches tall. They can turn themselves invisible and have a venomous bite. It is described that those who are bitten wither away. They live with the family and act as guardians who possess great strength, but freak out if anyone strays from tradition or acts poorly. This could range from a light prank to the killing and maiming of livestock, even people in some cases. It is also said that they can turn people into Tomtenisse to teach them lessons. This is from Wikipedia if anyone wants to contest these claims. With this I'm not quite sure what to do with them or if we should give them all these abilities that they're supposedly supposed to have. I would say that they should be a sentient pet who can only do dumb labor (hauling, cleaning, etc.) but are very fast and very vulnerable to fits of rage. I don't know what to do with their association to the winter solstice, but maybe we could just make them native to freezing biomes or something.
I have just found that they are often accompanied by a Yule Goat, and the modern versions of them act more like a cross between Santa Claus and a gnome.
