How do you learn to draw animal heads from any angle? Practice drawing them from three. If you master the front, side and three-quarter views, you will be able to interpolate any other head position. This also help you to visualize the head as a three-dimensional object rather than outlines around a flat shape. In this demonstration I construct three generic predator heads (two dogs and third that starts out dog-like and turns into a lion). Draw along with the demonstrations. As you do, notice how the same features appear from different angles. Then choose a few mammal species and draw their heads using photo reference (online image search) in all three views.
Click on the first image to start a step-by-step side-show.
Draw three circles, leaving enough room for adding noses and ears.
Add orientation lines, eye/nose line for side view, straight cross-hairs for front view, and curved cross-hairs for three quarter view.
Block in the length and position of the muzzle. For the three-quarter view, align the horizontal edges of the nose and chin with the edge at the base of the eye.
Add circles where the eyes sit below the skin.
Place the nose at the tip of the nostril. The back edges of the 3/4 view nose are parallel with the sides of the nose box.
Draw in the muzzle. Look for drooping skin around the corner of the mouth. The negative shape above the side-view is important to observe. it can be flat, angled up with a forehead as in this case, or angled back
Place the eyes. Predators have forward facing eyes. That means from the front you see the front (almond) view of the eye. From the side, the side view. Form the 3/4 view you see an almond shape in the near eye, but look carefully at the far eye, it will have a rounded edge on the far side.
Wrap the eye socket with muscles and cheek bones. There is a large bulge above the eye and a smaller one below the eye.
Carnivores have an extra pad of muscles between the eyes. Add a puffy whisker bed in the cheeks.
Draw the forehead. Use negative shapes to more closely observe the form. In the front view, the negative shape between the ears is incredibly useful to place the ears. In the 3/4 view the shape of the far side of the head is a good place to look. Place the ears at the back of the head. Think of the ear opening as and oval region instead of a straight line.
Place the ears. Look for where you see the front and back side of the ear.
The jaw line drops down behind the jaw. Get in the habit of drawing the neck.
The 3/4 view started out dog like but started looking more cat-like so I turned it into a lion. Notice the change of the nose shape and a large cat chin.