Yup, he's mad. I think perhaps he's mad at something that didn't know any better, like a kitten. And he wants to hurt it for doing whatever it did, but he can't because it didn't mean to do it. Ah, self control, how I love thine kitten-saving powers. It's funny to watch the mean dragon try his best to contain his anger... notice the clenched fist? Hee-hee! Look at him go!