The official Hellboy Animated Blog points the way to the first trailer for “Blood and Iron”:
Check out the first Blood and Iron Trailer over on YouTube. It’s a little dark and short but it gives you a taste of how different it is from Sword of Storms. I didn’t see the trailer until after it was done or there’d be latter retakes of some of the scenes. There’s also one scene that’s not from the movie. If you know your Mignola then you’ll have a clue to the extra special DVD extra that will accompany Blood and Iron.
You can watch the trailer here!
Source: Official Blog