Expressionless? I would say that it is anything but expressionless, but that's just my intake on it.
To me, it looks like he is tired or bored. It looks like he has a trace of a smile there, insinuating that there is something he finds humorous. Perhaps the irony that a creature such as him would feel such a way. He looks young, but intelligent. Perhaps in his teens, and it is well known that teens are known for their boredom.
All-in-all though, a brilliant piece of artistry.