This is like wondering why all Vulcans and Klingons don’t look the same. One thing that makes Nass look different is that his ears are tied together behind his head. You don’t really see them much in the movie.
In any case, Tarpals gets all the ladies with that 'stache. 😉
I’m confused by this post. What are images doing in this image thread?
JEDIT: Dammit LH!