Nick Burkhardt (David Giuntoli) and Hank Griffin (Russell Hornsby) will encounter a huge enemy as they face a 20-feet monster known as the Rat King in the 5th episode of Grimm. Trubel (Jacqueline Toboni) gets hospitalized following a severe injury while Nick will finally meet Meisner (Damien Puckler). Meanwhile, executive producer Norberto Barba reveals important details on the show's 100^th episode.

According to TV Line, a couple of Wesen who go sneaking around a dump wind up dead - courtesy of the Rat King - and Nick and Hank become involved when the Portland P.D. is called to the scene. In the picture posted on the site, Nick, Hank, Monroe (Silas Weir Mitchell) and Selina Golias (guest star Carlson Young from SCREAM) look up with mouths open, signifying a very tall height of the creature. Hank is also seen carrying a rifle.

In addition, the promo video posted on CDA News shows Hank saying "I don't like rats" and with the gun in hand starts shooting at the creature they call "Ratzilla" in a place that looks like a junk shop. On the other hand, Nick will be investigating this case not only as a cop but also as a Grimm since this is mystical Wesen creature on the loose on the streets of Portland.

Meanwhile, Nick has to handle other personal issues when a battered Truble shows up on his doorstep, passed out and now is hospitalized. Nick will also get to meet the infamous Meisner, as the image posted in the article shows Nick and Meisner back-to-back with clenched fists. Either both are fighting against each other or fighting together.

In another story, the cast and crew of Grimm has finished filming its 100^th episode. In an interview with Blastr, series creator and executive producer Jim Kouf revealed that the episode will be all about the keys. Executive producer and director Norberto Barba also said "Nick and Monroe go on a big trip because of the keys, and they find where the keys are. We see what the keys fit and we find out what's in that, and it's mind-blowing. It will change things."

Grimms Season 5 Episode 5 "The Rat King" will air on December 4 at 9pm on NBC.