Step 6: Draw a small arc with a diagonal orientation on the lower left side of the first circle as a guide for the blue whale's pectoral fin.
Step 7: Draw a triangle-like shape on the left side as a guide for the tail or flukes. To draw this shape, first draw a diagonal line on the left side, then connect the line on the body with two shorter diagonal lines.
That's it for the initial sketch! From this point on, press harder with your pencil to get a more defined sketch.
Step 8: Now draw the blue whale's eyes inside the head. First lightly sketch an oval. Use the lines as guides for placement. Darken the oval and make the ends pointier. Draw a couple of curved lines inside for the blue whale's eyeball. Shade in the inside of the eye except for the sides and a tiny circle to represent glare. Draw a few lines around the blue whale's eye as the wrinkles and folds of skin.
Step 9: Use the initial lines as guides to draw the blue whale's mouth and lower jaw. The mouth starts under the eye. Follow the basic path of the guide line but curve the line up more. Sketch lightly to get the line right. When you get the structure of the blue whale's mouth right, darken the line. Continue the line under the mouth to create the lower jaw. Follow the basic path of the arc as you darken the line. Make the jaw a bit thinner than the initial arc.