" Lycanthropia " is the 14th episode of Season 5 of the supernatural drama series Grimm , which first aired on March 25, 2016.

In this episode, Nick and Hank investigate a brutal double murder in the woods that leads them to a rare and terrifying known as Lycanthropia . This condition is a genetic mutation found only in Blutbaden that causes them to become temporarily insane and violent during the three nights of the full moon.