Most, if not all, of the references and names are derived from German terms or real scientific terms. For instance, "Blutbad" means bloodbath, "Hexen" means witches, "Schaden" means misfortune or misery, and "mellifer" means honey-carrier. The terms are, however, not original German terms for mythological creatures. They've been made up for the series and most of them are "incorrect" German. Despite the NBC page translating "Schneetmacher" as a cold, evil person, for example, such a word does not exist in German. The queen of the mellifer is referred to as "Mellischwuler", which, translated, means "Melli-gay man" - a possible explanation for this might be that the word "queen" was mistyped "queer" when the word was looked up in a dictionary. Many "Wesen"-names are made up compound nouns, but often grammatically incorrect. Examples for this are the "Bauerschwein", "peasant pig", which -correctly composed- would be a "Bauernschwein" (in any case another creature name that does not exist in the German language of any time period). The same goes for "Spinnetod", which, correctly composed, would be "Spinnentod" (spider death). The right plural for Blutbad (blood bath) would be "Blutbäder". In the pilot episode, the Reaper Hulda carried a scythe that read "Erntemaschinen der Grimms", which translates as "Harvesting machines of the Grimms".
Neither Wu nor Monroe are referred to by their given names.
Each episode opens with a quote from various fairytales or folk stories, which relate to the episode in some way.
At the 2013 comic con panel, the producers stated that Volcanalis was not a wesen but "something else entirely different."
The term 'wesen' is pronounced with a 'v' instead of a 'w'.
'David Guintoli' (Nick Burkhardt) stated that he loves playing Nick because he gets "paid to brood."
According to Kelly Burkhardt, the Grimm trait is not strictly hereditary. Some offspring of Grimms have it and others don't. Girls also realize it earlier than boys.
Filmed on location. The cast stay in nearby apartments while filming.
It was revealed at Comic Con that actual descendants of the Brothers Grimm reside in Portland. The producers had no idea until a member in the audience told them.
Russell Hornsby and Sasha Rioz appeared on the ESPN TV series "Playmakers" before joining Grimm. Hornsby played Leon Taylor, the aging running back and Sasha Rioz played young offensive coach Stephen Lyles.
There is a stained glass image of a wolf on Monroe's door; fitting as Monroe is a "blutbad" or "big bad wolf".
The basis for this episode and the origin of the opening quote comes from "Little Red Riding Hood."
The basis for this episode and the opening quote come from "The Story of the Three Bears."
The basis for this episode and the opening quote come from "The Queen Bee."
Doug is wearing a shirt that has black and yellow lines on gray and white-ish base. His cell phone has a black-and-yellow shell. The queen is dressed all in black and yellow. All references to the colors of bees.
The basis for this episode and the opening quote come from "Bluebeard."
The goat is called 'Wesen Billy Capra', "Capra" is the name for the taxonomy group that contains all species of goats; Billy is a term used to describe male goats.
The episode's title comes from Camille Saint-Saëns piece of music by the same name. It is also played by the musicians in the story.
The basis for this episode and the opening quote come from "Pied Piper of Hamelin."
In this episode, Angelina, a Blutbad, mentions being with someone named Adam Hauptman. Adam Hauptman is the name of an alpha werewolf from the Mercedes Thompson series written by Patricia Briggs.
The basis for this episode and the opening quote come from "The Three Little Pigs."
The piggy arson investigator is Paul Orson, a nod to the Latin taxonomic term "porcine," meaning pig.
In this episode it's stated that Monroe went to grad school at Brown University.
The basis for this episode and the opening quote come from "Rapunzel."
This is the first time Monroe visits Aunt Marie's trailer.
The episode title is a pun on the name of John Steinbeck's 1937 book "Of Mice and Men". It has been filmed in 1939 (cinema), 1968 (TV), 1981 (TV) and 1992 (cinema).
Amy Acker, who guest stars in this episode also starred in the series "Angel" which was co-created by Grimm's co-creator David Greenwalt.
The first time the term "Wesen" is used.
The plot alludes to the classical tale of Androcles and the Lion, though it doesn't follow to the same outcome.
The opening quote comes from Aesop's fable "The Slave and the Lion".