The paranormal thriller - which airs on Watch in the UK - has always attracted a high calibre of guest actor and this year David Giuntoli, Russell Hornsby, Silas Weir Mitchell and co will be joined by the likes of James Frain (True Blood, 24) and Mark Pellegrino (Lost, Supernatural).
Join us now as we take a look back at some of Grimm's greatest stars ahead of season two's UK launch - it reads like a Hollywood Walk of Fame for cult and fantasy television!
Fred Koehler in episode 1.09 'Of Mouse and Man'
Koehler - whose cult credits include roles on Torchwood and Lost - played a mouse-like creature in Grimm's ninth episode, but there was nothing meek about his character Martin Burgess, an emotionally unstable serial killer who was lashing out at the world after years of childhood abuse. It was the realisation that he was becoming more and more like his abusive father that eventually allowed the cops to capture Burgess.
Daryl Sabara and Hannah Marks in episode 1.10 'Organ Grinder'
Grimm updated the classic tale of Hansel and Gretel in its tenth episode, which saw Spy Kids star Sabara and FlashForward's Hannah Marks play a pair of homeless teens. Hanson (Sabara) and Gracie (Marks) both had to be rescued by Nick (Giuntoli) and Hank (Hornsby) from the clutches of the sinister Doctor Levine (Valerie Cruz), who planned to harvest their organs!
Amy Acker in episode 1.11 'Tarantella'
Angel and Dollhouse veteran Acker played Lena Marcinko, a spider-like Spinnetod who had to feed on young men to stop herself from rapidly ageing. Ultimately captured by Nick and Hank, Lena was left to rot in a jail cell...
David Zayas in episode 1.19 'Leave It to Beavers'
Puerto Rican actor Zayas - best known for his role as loveable 'tec Angel Batista on Dexter - popped up in one of season one's final episodes as Salvadore 'Sal' Butrell, who is secretly a troll-like creature known as a Hässlich. Butrell made a mistake when he targeted Nick but ultimately survived the events of the episode - perhaps a return appearance from Expendables star Zayas is on the cards?
Roger Bart in episode 1.21 'Big Feet'
Bart - known for his role on Desperate Housewives but perhaps more familiar to cult TV fans for playing Vice-President Richard Peel on The Event - appeared on Grimm as a Wildermann doctor who was conducting some seriously unethical experiments. It all ended badly for Bart's character Konstantin Brinkerhoff, who met his demise after going on a wild rampage.
Grimm returns to Watch on Monday, October 22 at 9pm on Watch.