It was claimed at Comic Con that actual descendants of the Brothers Grimm reside in Portland. However there are no descendants of the brothers who compiled the fairy-tales, so the fan was mistaken or lying. Many people want to believe they are descended from the Grimm brothers, and the genealogists give the same answer - the Two Grimm brothers have no living descendants, Jacob had no children, and Wilhelm had no grandchildren, so their line ended there. However the Grimm family of Jacob and Wilhelm had more siblings who however were not working on the fairy-tales, e.g, their only sister Charlotte Grimm (1793-1833) who had 6 children, painter and copper engraver Ludwig Emil Grimm (1790-1863) or writer Ferdinand Philipp Grimm (1788-1845). So anyone who can actually trace their family back to a family called Grimm can only be (at best) a descendant of one of the brothers siblings. The surname Grimm does not mean someone is related to the Brothers Grimm; it was hardly a unique surname.
Whenever the episode includes a room number (hotel room, hospital ward or bed) or address, the number is the combination of the number of the season and of the episode. For example, the hotel room of Adalind was shown first in episode 12 of season 2, and the room no. was 212.
David Giuntoli and Bitsie Tulloch grew to love Portland so much, they relocated out of L.A. and stayed in the Pacific Northwest, even after the series ended.
David Giuntoli (Nick) and Elizabeth Tulloch (Juliette/Eve) announced their engagement at Comic-Con in San Diego.
The medical clinic in the episode Organ Grinder is called Folter Clinic.
"Folter" is the German word for "torture".