Bake cake according to package directions. Prepare to be covered with fondant by lightly icing with buttercream.
Cover face with skin tone combination color fondant. Cut out where mouth is and cover area with black fondant.
To make gums, use Red-Red/Brown combination fondant and make two thin logs and attach with damp brush. Lighten skin tone with a small amount of white and cut out teeth; attach with damp brush. Roll two logs for lips; attach with damp brush.
For eyes, roll two 1 1/4 in. balls and attach. Use large opening of a standard tip to cut out skin tone eyelids and attach with damp brush. Roll thin logs for eye muscles and attach from eyeball to socket.
Use modeling sticks from kit to imprint wrinkles and details. Brush Black, Red-Red and Ivory icing color details to add dimension to face.