Naraku always looks mad. XD Maybe he was just...carnally frustrated.

(Actually, the monkey in Japan is known as the trickster or deciever, and since white is supposed to represent purity...I think it's supposed to basically stand for the fact that he's actually evil, but tries to appear good at first in order to trick others. Or hell, who knows? Maybe it means that he's actually NOT evil inside.Crazy world.) Love the picture.