Interview with artist Duncan Fegredo.
Gotta love how he says he'd rather see all-Mignola drawn Hellboy comics. Although I have to say, I really like the work he's been doing on the Wild Hunt and Darkness Calls. And I think it's funny how he struggled with how to draw Hellboy's tail while the character's on horseback, and Mignola told him to lose it in shadow and not draw it, and he apparently couldn't resist the challenge and drew it anyway.
(I snagged this article and the previous one off of the Comic Resources Board) -- there's a whole series of articles over there.