The animal kingdom is full of weird specializations and features. A mutation happens and suddenly an animal has a different color, or a new feature. A stronger jaw, a higher top speed, you name it. Specializations are caused by little errors in the DNA of an individual. Most of these changes go completely undetected, but sometimes they’re very evident. More often than not this mutation doesn’t change much about the animal, but when it does it either means the demise of this animal, or success. And when success hits, this specific animal will likely be able to have more offspring than it’s other species members.
Character design is a favorite subject for many artists. Knowing what you’re doing while you’re at it is incredibly helpful. Find out more about this subject, and its close relative: Creature design.
Knowing where to go when you want to become a self-taught artist isn’t easy. Some people choose to base all their knowledge on one artist or one course. I recommend though to look up several artists. Learn to see things in different perspectives, and see what fits you best at that time.