Step 11: Under each leg, draw a smaller U-shaped arc as guides for the gorilla's feet. Pay attention to the size of these arcs in relation to the arcs above them.
That's it for the initial sketch! From this point on, press harder with your pencil to get a more defined sketch.
Step 12: Lightly sketch two small ovals inside the gorilla's head for the eyes. Use the construction lines to help with placement. Draw a dark curved line above the eye on the left for the heavy brow. Darken the edge of the eye too but make the sides pointier. Add a dark line over and below the eye on the right. Darken the eye itself too. Draw a few small curved lines between the eyes to emphasize the furrowed brow.
Inside each eye, draw a small circle for the irises. Darken the section of the eyes outside of the irises. Shade the irises too but leave a tiny circle blank to indicate glare. As you shade the irises, use a value that's lighter than the section outside of the irises. Add a few more lines above the eyes to further emphasize the furrowed brow.
Step 13: Draw the nose between the horizontal construction line and the lower edge of the half-circle. The shape of the nose should be similar to the letter m. Notice how wide the gorilla's nose is compared to the eyes. Sketch lightly at first and darken only when you get the shape right. Inside the nose, draw two small slits for the nostrils. The slit on the right should be smaller because of perspective.
Step 14: Draw a long, curved line under the nose for the open mouth. The line starts under the nose and is shaped similar to the letter C. The line should be long because the gorilla's mouth will be wide open. Don't draw the right edge of the mouth yet.