Since Alec d'Urberville is described as a Victorian villain, there are images of this stereotypical villain on the internet that you can use as a model. An inexpensive way to construct a character is available at hobby craft shops, or even at big discount stores that have a crafts section. For instance, there are styrofoam balls and other shapes that you can put together. For instance, use a cylinder-shape for the body and a ball for the head. Arms and legs can be formed by using little pieces of wood glued together. You can make clothing with those squares of felt or quilting material that are sold at the discount or craft stores. If you create the face, little beads can act as eyes, etc. Drawing the mouth is certainly an option.
Use that description of Alec from Chapter 5 of Tess of the D'Ubervilles:
He had an almost swarthy complexion, with full lips, badly moulded, though red and smooth, above which was a well-groomed black moustache with curled points, though his age could not be more than three-or four-and-twenty. Despite the touches of barbarism in his contours, there was a singular force in the gentleman's face, and in his bold rolling eye.
Or, find a an image that fits Alec and copy it. You can even find a face the size you need (or size it to fit) on the internet and copy it and attach it to the head. Find something that looks like black "hair" and form the moustache and head hair. Use your imagination and discuss your ideas with a salesperson who knows about crafts. Good luck!