Zach has a trianglar-shaped face with black hair and green eyes. He almost always wears a black sweater, except in the episode "Mystery of the Weird Looking Walrus", when he wore a black trench-coat and a gray sweater. He also has REALLY pale skin, but when he's really hot, it turns birght red, as showed in "Bass Class". In "Tazzy Chris", when Zach had a flashback from his child hood, he is shown to have regular colored skin, with braces and freckles. Unusally, in the episode "Polar Bears Don't Dance", his eyes are light shade of green than other episodes.
(To be continued. I'm too lazy to finish.)