It's easy to describe what a non-human character says and does, but thoughts and perceptions are another matter. How do they see the world? What do they think of, say, human civilization and motivations? Suppose they have a tail- how do they feel about it? What would it be like to have a wolf's sense of smell? What does it feel like to have thick fur or scales? Suppose they were cold blooded, like Mr. Saria, in one of my published stories, trying to function in a world of warm-blooded humans. Suppose they were thousands of years old? What do you think?