I found a helpful glossary in the back of Just Qvigstad’s book. There are so many fantastical spirits and forest creatures in Sami traditions and in the general folklore of Scandinavia that it is difficult to keep them all straight. My definitions are paraphrased translations combined with what we’ve learned from Just Qvigstad’s writings so far. I am learning as I go, so I don’t know much more than what I’ve written in blog posts so far.
Stallo: An evil spirit in Sami mythology. The Stallo is also stupid. On Christmas Eve, they ride reindeer sleighs, snatch children, and drink blood from the heads of those foolish enough to not leave sliced meat and water out for them on their tables. Stallo have a large, warrior-like bodies and may have Viking origins, or may be a hybrid of Sami and Norse mythology.
Halde: An invisible spirit common in Sami tales. They have no body. Halde are mentioned a lot in Qvigstad’s summary of Isaac Olsen’s journal from the early eighteenth century. More on them later….
Vetter: Another creature common in Norse myth. I have never heard of these before. Stay tuned…
Seida: An object in which a spirit can exist, such as the rocks that the Sami believed had spirits in them. The Scandinvian folklore traditions of tomte, nisse, and trolls add to the confusion. I will try to separate and define these as I go along. My favorite source for Norse mythology, Dr. Jackson Crawford on YouTube, says to differentiate the Norse mythology of the Viking Age from Scandinavian folklore which originated in the 1600s and later. Sami traditions overlap both the Viking Age and the folklore age, so I will try to be careful to distinguish the origins of these creatures as I go.
Source: J.K. Qvigstad, Contes de Laponie, adaptation en français par Jacques Privat, Editions Esprit Ouvert, 2008, p. 207-208.