In the tales of the Norse, there are many forms of shape-shifting. Two types stand out: bears and wolves. Some of the most famous images of the Norse themselves are bound up in images of bear and wolf shape-shifters. Yet, examining these more closely, one finds a pattern that emerges: ursine shape-shifters are more upstanding, heroic, and positive, while lupine shape-shifters are more ambiguous and ambivalent. This paper analyzes how experiences with the natural world, as well as older folklore, belief, and culture in the region, informed notions of shape-shifting and hybridization in the great Norse tales, with lasting impacts on belief for many centuries afterward.