Horses' ears - a quick guide
Here is my first commented sketch! I chose horses because they are my favourite animal, and their ears because they are a wonderfully expressive mean of communication. Do you want to make your horse look attentive and curious? Point its ears forward. On the other side, backward ears show fear or aggressiveness. Every horse breed and every individual has slightly different ear shapes - with a curly point, round, long, short; foals tend to have large ears in proportion to their head size.

Tip for practice: pick a bunch of horse portraits and copy only the ears! Or even better, visit your local stable or your own horse for a bit of real life practice :)