Step 11: On each side of the mask where Sub-Zero's cheeks should be, draw an oval. Inside each oval draw a curved line. This line makes the ovals more like three-dimensional holes on the sides of Sub-Zero's mask.
Step 12: Finish up Sub-Zero's mask by drawing a couple of lines that extend from the ovals toward the back of the head. The lines should get narrower the farther back they go. Draw another smaller curved line inside each oval for extra detail.
Step 13: Draw the hood over Sub-Zero's head by using the top of the initial circle as a guide. Darken the top of the circle and make the sides a bit more narrow. Then draw a wavy line above the eyes for the hood's opening.
Step 14: Draw an extra line parallel to the hood's opening for a thicker appearance on the edge of Sub-Zero's hood. Draw a couple of curved lines inside the hood for extra detail and so there isn't too much empty space on Sub-Zero's head.
Step 15: Draw some lines throughout Sub-Zero's head and face for extra detail. Draw a few curved lines within the hood to simulate his head inside. Draw a couple of lines around the eye on the left side for Sub-Zero's scar. Also draw some lines under each eye for extra detail.