I always imagined tehdude as having short black hair underneath his hat/crown. Also, I've always invisioned him as being relatively young (aproximately the same age as the KotOS members); he's by no means a kid, but he's definately not old enough to go bald. :P Also, when reading tehdude's dialogue, I say his words in my head with a very specific voice. Unfortunately, there is no way for me to share with you this voice in this message. :P But I can tell you that his voice always rises to a shriek whenever he is angry.
-N_B