Nokk are, according to Germanic legend, shapeshifting water horses which lure men to their deaths. In the Frozen 2 trailer, however, the Nokk saves Elsa instead of drowning her.

Disney released Frozen 2's trailer on YouTube, and it shows Elsa and Anna in some trouble in Arendelle, partially because of a water horse. See the first trailer and Frozen 2 theories here.

It opens with Elsa swimming up through a deep body of water, encountering what appears to be a phantom horse before breaking the surface. We then hear Pabbie (Ciaran Hinds) talking to the sisters ...