Step 10: Draw a series of tiny triangles along the inside of the open mouth for the sperm whale's teeth. Stop drawing the teeth before the line ends on the right. Leave room at the top for more teeth. Draw more small triangles along the top edge of the lower jaw for another row of teeth.
Step 11: Use the big arc on the left side as a guide to draw the rest of the sperm whale's head. Darken the path of the guide to create the shape of the blocky head. Curve the line to the right toward the mouth before you hit the bottom of the guide. This line doesn't meet the top of the whale's mouth but curves under it, just above the teeth.
Step 12: On the top, left side of the sperm whale's head, draw a short, curved line for the blowhole.
Step 13: Use the U-shaped line in the middle of the body as a guide to draw the sperm whale's flipper. Darken the guide but make the bottom part narrower. At the top close up the shape a bit more and add some lines for creases.
Step 14: Use the remaining lines and shapes as guides to draw the rest of the sperm whale's body. Simply darken the outer edges of the initial guides to create the shape of the body. Don't overlap the shape of the flipper as you darken the lines for the whale's body. Don't darken the tip of the guide on the lower, right side.