Ulda
The Ulda (also called Gufihtar, from Old Norse gud vätte 'good underground being') are a mythical race of underground people in Sami folklore. They live inside fells and beneath the earth in a parallel world called Saivo. They are rich, beautiful, well-dressed, and possess all gold and silver under the earth, including hidden treasure. Their reindeer are of exceptional colors and leave no tracks in snow. Tradition says you can claim an Ulda reindeer herd by throwing a metal object over it. They sometimes swap their children for human babies (changelings). If a human eats or drinks in the Ulda