Metamorphosis and shapeshifting are frequent themes in folktales, but also in Old Norse literature, in poetry as well as in prose. They exist in mythological as well as semi-mythological contexts, in dreams or in the more realistic narratives told of in the Icelandic sagas. This article concerns themes of shapeshifting from The Poetic Edda (Eddukvæði), The Family sagas (Íslendingasögur) and The Legendary sagas (Fornaldarsögur Norðurlanda). These sources were written down in Iceland, mostly in the 13th-14th centuries, but were preceeded by a widespread oral tradition going back at least to the Viking Age. Shapeshifting stories were certainly entertaining when performed, thus the perspective of the contemporary medieval audience may be taken in account. This study also analyses whether shapeshifting seems to be gendered, and whether the change in nature is due to self-shifting or external influence – and how it was done, for example by words or gestures. Besides, shapeshifting connected with social categories, even with some hierachical perspective is discussed. The terminology used to describe shapeshifting is exemplified, and the context of the shapeshifting narrative is considered, for instance whether time and space may be of importance, as well as the consequences.