TV Guide reports that actor C. Thomas Howell (best and most favorably known for drinking deer blood in the original Red Dawn) may be dropping by Portland to guest star on Grimm. From TV Guide:
The Southland and Criminal Minds alum [AND RED DAWN!!!—Steve] will play FBI agent Weston Steward in Episode 18. Because of his experience and capability, Prince Vikton (Alexis Denisof) views Weston as an invaluable resource when stateside issues need to be handled swiftly and precisely.
So be on the lookout for C. Thomas Howell in the near future. (He'll be the one handling things swiftly and precisely... aaaaand might have deer blood dribbling down his chin.)