Fossegrim

A Fossegrim (FOS-uh-grim; Nor. Foss "waterfall") is a Wesen who is known for living in waterfalls and playing the fiddle. They are willing to teach others to play once they gain their trust.

As Hank and Nick looked through some Grimm Diaries in the trailer for any possible information on a Wesen that could freeze its victims, Nick found some pages in one of the books describing the Fossegrim.

Trivia

 * This Wesen is based on Nordic mythology, which describes the Fossegrim (known as "grim" in Norway and Strömkarlen in Sweden, which means "river man") as a water spirit or troll that is exceptionally talented at playing the fiddle.