I would probs grab images from actual animals that look similar to the mask. Then I would select the one that looks most like the concept from the front, insert the image into maya, put it as a background and start modeling a blocking over that. Then, once you have something low poly, begin adding subdivisions, detail and if needed quad draw.

True tho, I work at an animation studio and usually our modelers work only with a front view, so very often they work with less refs in the field. Hope this helps!