You should look at the "Van Helsing" characters at Runtime DNA. They are obviously similar to the movie, but not too similar as to be copyright infringement. I think they call the Van Helsing character "Beast Hunter." The point is you can't copyright a "vampire hunter" but you can copyright "Van Helsing." A model with Hugh Jackman's face would obviously violate copyright (or Hugh Jackman's right to promote his image), but a guy with long hair in a trench coat with a crossbow? Not copyright infringement. The reason people get busted for aliens ripoffs is because the models are pretty specific and exact copies.