The Green Knight
The headstrong nephew of King Arthur (Dev Patel) embarks on a daring quest to confront the eponymous Green Knight (who, in case you lost track of your notes from your Medieval literature class, is the verdant-hued creature who rides into Camelot on New Year's Eve and challenges a member of the court to strike him once with an axe—on the condition that he can return the gruesome favor the following year—in the 14th-century chivalric romance Sir Gawain and the Green Knight).