makeup or mask ideas for the beast

Well, that could work, but that mask doesn't have any fangs! What I suggest is building up a clay sculpture of only nose, cheekbones, and mouth with fangs on a lifecast of your actor. Lifecast tutorials for facial prosthetics such as these can be found online. Use the same mold for both your appliances and mask, once you mold both sides of the actor's head, you trim it for the appliances. For the mask, only trim some of the bottom so that the mask fits over the ears, like an over-the-head mask, then attach the hair and stuff, and remember, always use either PAX Paint or the better and less work option, Rubber Mask Grease Paint, it works on skin and latex. Either that, or buy a cowl and prosthetics from either fxwarehouse.info or toxicimage.com, glue them together, and paint them with RMG Paint and add hair. It probably won't be cheap, but it will be the best solution.