Muuntoperään

Muuntoperään is a figure from Finnish folklore that appears most often in regional tales of southeastern Finland. The name comes from muunta, meaning “to change or transform,” and perä, which can be interpreted as “tail” or “back end,” implying a creature that can shift its physical form or eerie appearance. In the folk tradition muuntoperään is described as a small, semi‑human being that can mimic the likeness of a household cat or dog and then assume a more sinister shape when it feels threatened or playful. Witnesses in the 19th and early 20th centuries often reported occurrences of a creature whose size was that of a small animal but whose features changed unpredictably. The animal was sometimes said to hollow out cottages at night, and sometimes it was viewed as a trickster or omen of ill luck.

Scholars have examined the muuntoperään tales in relation to similar shapeshifting beings in other Northern European traditions, such as the Norwegian “orfe” or the Norse “Húlfr” (wolf‑man). The motifs are thought to be part of a broader pattern of folk explanations for unexplained animal sounds or strange footprints near houses. The most common narratives locate the muuntoperään in pine forests and marshy bogs, where the animal's ability to blend into its surroundings could be described as a form of natural camouflage. Contemporary accounts of muuntoperään rarely appear, although some modern Finnish storytellers and regional museums keep the legend alive by including it in collections of folk spirits.