While it suffered a slow, wobbly start, with its delay due to the 2008 writer's strike and its disconnected, messy first few episodes, NBC's Grimm quickly picked up the pace and took off only like many great series with shaky pilots have done, earning it a devout fan following and a reputation as one of the best fantasy shows on television. Once we got past the initial exposition and a bit of confusion, Nick Burkhardt found his footing and impressed us by balancing his role as a Grimm and a cop who had to toe the line between the law and the monster.

A crime drama about favorite Brothers Grimm fairy tale characters, from Red Riding Hood to the Three Little Pigs, Grimm also employed mythology and monsters from cultures around the world, from Krampus to La Llorona. Producers were quick to note that Grimm wasn't meant to be a fairy tale-based show, like Once Upon a Time, but a crime series that happened to involve Wesen, creatures only a Grimm can see. The fresh take on myth and magic, combined with political intrigue, vengeful witches, and the complicated relationships of the characters made the show highly addictive by the middle of the first season.

While it continued to have its ups and downs between its creatures of the weak and controversial character development, Grimm ran for a solid six seasons, and much of its success stems from the hard work creators and actors put into bringing it to life.

Here are 25 Things Only True Fans Know About The Making Of Grimm.

Nick's Mom Was Offed Due To Scheduling Conflics

Some women in Grimm were offed due to circumstances beyond writer/director control, such as Mary Elizabeth Mastrantonio's schedule. Plots were planned involving the talented actress but she wasn't able to continue to travel on location, so she was cut.

Of course, we can see many different ways of handling this, from bringing her back later or having her work from afar rather than having her head chopped off, which seemed rather extreme. To some of her fans, it even felt like a punch in the gut, and they thought that she deserved a better send-off.

Room Numbers And Addresses Are Mashups Of Episode And Season Numbers

This is a fun piece of trivia that many fans have noticed over the years of watching Grimm. Every time an episode has a room number, address, or other location with a number in it, the number is a mashup of the episode and season.

It's such a fun fan Easter egg that we suspect there was even an inside joke during one season. When Trubel remarked that someone was in room 406 and Nick asked how she knew that information, she gave a little laugh, which many fans take as a nod to how the actors are quite aware of this little ritual.

Wesen Names Come From Real Germanic Words

To keep the series as authentic as possible to the Brothers Grimm, whose stories were largely collected in the Black Forest of Germany, many of the words, particularly the Wesen names, are derived from that language's words. Fuchsbau, Rosalee's species, translates to "fox hole" or "burrow," while the "big bad wolf" Blutbad, like Monroe, comes from the words "blood" and "bath," which really don't fit our favorite vegan wolf very well.

A Hexenbiest means "witch beast," while a Zauberbiest means "magic beast" or "wizard beast." Speakers of the language do like to point out how the terms are awkwardly pronounced on the show, though!

Claire Coffee Was Really Pregnant in Season 4

While several Grimm stars have been pregnant while filming the show, each was handled differently in terms of production. When Bree Turner, who stars as Rosalee on the show, was pregnant during the second season of the show, she simply wasn't filmed as much. When Claire Coffee became pregnant during season four, the writers ran with it, using it in the story line with Nick and Adalind's baby.

Both Turner and Coffee weren't meant to have such prominent roles on the show, either, but both became regulars featured nearly episode due to their popularity.

Sergeant Wu wasn't supposed to be so important

Sergeant Wu is one of the show's most beloved characters. Whether he's wisecracking, poking fun at Nick and Hank for arriving at the crime scene later than he got there, or going mad over not understanding what was going on with the Wesen, Wu is a very likable character.

Reggie Lee wasn't supposed to have such a large role on the show, but the writers loved him so much that they wrote him in much more often, giving him his own arcs, such as the Lycanthrope story, and ensuring that fans got enough of his one-liners.

Eight Different Babies Played Kelly

Kelly, Nick's son with the hexenbiest Adalind, who tricked him into sleeping with her by posing as his girlfriend, Juliette, was played by a total of eight babies for the show. Although Kelly is a boy, six of the infant actors were girls.

There's really no way for the audience to know otherwise. Claire Coffee, who plays Adalind Schade, says that they were all equally adorable and luckily easy to work with. She also enjoyed working with the babies because they helped her scenes go more quickly.

It had a different name and network

David Giuntoli and cast in Grimm Series Finale

The Writer's Guild of America Strike of 2008 had some heavy impact on entertainment in general, from nixing regular entertainment awards that are normally run on TV to causing the layoff of hundreds of support staff. Prior to the strike, Grimm was originally planned to air on CBS in 2008 with the name "Brothers Grimm." It would be interesting to see how that concept would have played out and any differences between the Grimm that almost Was and the Grimm fans got.

Since CBS had the strike going on, the show was ultimately delayed until 2011 when NBC picked it up.

Barney Burman Made The Wesen

Fans of Star Trek, Planet of the Apes, the Men in Black series, and other sci-fi adventures know that it takes someone with wicked skills to bring movie monsters to life. Luckily Barney Burman, who worked on all of those productions and other favorites, like How the Grinch Stole Christmas, worked on Grimm.

Burman says that knowing both makeup and prosthetics just makes him better at both arts, and we are inclined to agree. He's mastered the art of both makeup and prosthetics in a way only a true expert can.

Filmed on location in real forests

One of the best things that makes Grimm feel so real is that it was filmed in the actual region where it takes place. When we see Nick chase Wesen through Washington Park or Forest Park, Oregon, that's where he's actually running down his suspects.

This lush location gives us not only the gorgeous background that brings fairy tales to life, but it makes the chase seem all the more real, whether Nick and his partner are looking for a missing person or a dangerous beast only a Grimm can take out.

Halloween Season

Sometimes the release of media is crucial to its success, and when the premiere of Grimm, which was originally scheduled for September 30, 2011, was moved to October 28, it was purely to bank on the spooky upcoming holiday to help increase viewer interest. This turned out to be genius marketing, given that it resulted in 6.56 million viewers, more than any other episode that season.

Grimm also has a history of excellent Halloween episodes, particularly when they feature blutbad Monroe (Silas Weir Mitchell) taking on particularly wicked trick-or-treaters and engulfing his home with seasonal decorations.

Sean Hayes Was A Co-Executive Producer

One of the reasons why Grimm ended up being so successful was that its executive producers, including Sean Hayes (of Will & Grace fame), were so intent upon making it happen. Having pitched the idea with Todd Milliner back in 2005, not only was he ahead of the big fairy tale resurgence in TV and film, but Hayes was also persistent enough to make it happen after years of setbacks.

With the idea of a show that was dark and scary but still fun, complete with monsters and the ever-popular crime show twist, they truly created a new spin on the Brothers Grimm.

Guest stars with incredible pedigrees

Grimm has employed some guest stars with serious acting chops in the past, lending those episodes some extra star power. Amy Acker, a TV star known for her roles in everything from Angel to Alias to The Gifted, played an incredible spider-woman in the episode "Tarantella". The Wesen has to feast on young men in order to remain young, giving her some wicked scenes.

Reg E. Cathey, of House of Cards and The Wire fame, played The Baron Samedi from Haitian Hoodoo in several episodes throughout the lifespan of the show. He woges into a puffer-fish-like creature known as Cracher-Mortel and is the main bad guy in a few episodes.

Wesen are supposed to be human-like

When it comes to movie monsters, we often get cold, creepy creatures who haunt our nightmares but have little to no humanity in them. That's the big difference the show made with its Wesen, or fairy tale creatures. According to special effects artist Barney Burman, Wesen were designed to appear as warm and humanoid as possible, from their ears to their teeth.

The prosthetics, which took around 20 minutes to mold per face, weren't cold and clammy, but designed to help make each Wesen seem lifelike and relatable. Many Wesen are harmless, just trying to live their lives like anyone else, and this really helped push that point across during show development.

The Wesen Council is really The Peace Palace

Not all of Grimm takes place in the Portland area. The Wesen Council, which governs the Wesen and ensures that they follow their laws, don't even live in the United States, but in Europe. To create a more authentic feel, the shots taken of the Wesen Council were at the Peace Palace in the Netherlands.

It's a beautiful administration building in The Hague and really brings and old European feel to the episodes where we witness the Council making decisions, whether they are compromising with the Royals and Grimms for the greater good, or plotting out an end-of-life sentence as punishment for a crime committed.

Adalind vs Juliette

David Giuntoli in Grimm Series Finale

Co-creator Jim Kouf says that makers were very protective of our beloved Grimm characters, but it seems like that is not completely true. We witnessed some characters, most notably women, treated unfairly or even offed after torment every season. Nick's girlfriend Juliette stuck by and was tortured and nearly offed several times only to be made the villain. Nick's mother returned only to be beheaded shortly thereafter.

While it's true that many fans found Juliette Silverton a bit dull, once she became aware of the Wesen she should've been made Nick's partner, not replaced by Adalind Schade, who caused most of the pain in the show and took away Juliette's agency in the first place.

Aunt Marie's trailer is bigger on the inside

If you've ever thought that the inside of Aunt Marie's trailer looks a little big to fit inside the little trailer we see from the outside, you're absolutely right. An entire larger set was constructed of the inside of the trailer in order to accommodate all of the weapons, potions, books, and other gear that Marie used in her career of fighting Wesen.

The actual size of the trailer on the outside would be way too tiny to house all of those scythes, machetes, and labrys, but it was easier to get in the shots and looked good in each scene.

Real Descendants Of The Brothers Grimm Live Where The Show Was Filmed

The Brothers Grimm

Although writers and producers had no idea, the location where Grimm is filmed is actually home to descendants of the Brothers Grimm in real life, giving their project even more credence. At a 2013 Comic Con open Q&A session, an audience member revealed that there are actual descendants of the Grimm brothers living in the city of Portland, where the show takes place.

Even if it was a serendipitous decision and no one had known that Portland actually had a connection to the fairy tales, it's still a fun fact about the history of Grimm.

The spin-off comics and book series

Like Buffy, Supernatural, and many other cool fantasy shows, Grimm has its own fictional books and comic books that have been written to further the show. From 2013 to 2014, Dynamite Entertainment released 12 comic books, and three different Grimm novels were written between 2013 and 2014.

Each book was written by a different author; John Shirley wrote The Icy Touch, John Passarella authored The Chopping Block, and Tim Waggoner wrote The Killing Time. The novels are based on the TV show and each writer was hired to write a work that would complement the program.

The Monster Of The Week Format didn't last

To keep the show easy enough for fans to follow along with, writers originally gave the show a monster of the week format similar to the one that Supernatural also initially followed. While there was still a story to keep up with as Nick learned the ropes and said goodbye to his aunt, most of the show was still easy to follow, focusing on the different types of Wesen Nick would encounter and how he learned to deal with seeing them.

Once a few episodes were under the show's belt, the writers delved into deeper, more intricate story lines but the weekly creature still remained something fans looked forward to seeing.

The Creators Say That Nick's The Character Who Doesn't Change

According to the showrunners of Grimm, each character undergoes some significant change throughout the seasons-- except for Nick. Nearly everyone changes to some extent, whether it was Sergeant Drew Wu's Lycanthrope scratch or Adalind Schade shifting from the worst antagonist on the show to Nick's love interest.

They admit that the women of Grimm undergo the most radical change in the series, but its main protagonist, Nick Burkhardt, generally doesn't change. When they met up to decide what the characters' fates will be, this was pretty much agreed upon as a given part of the show.