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 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.