Appearance/discussion of Necropolis units.

I'm puzzled by such a terrible thing as the "smoke" around the Ghost Dragons... what is that black smoke around the skeleton? It looks like some kind of plague; maybe the authors meant it to represent negative energy and evil swirling around? And the green plague around zombies and skeletons is just ridiculous! And the mist coming from under the Death Herald's robe? Is he a teapot, that he's emitting steam? But overall, the units are well-designed and not bad. My rating is 4+ or 5-.