Scott Ian is not scary. In fact, I'd say that your musical respect/credibility is inversely proportionate to your appearance on any VH1 "Hey, Remember The ..." programming. Which means Scott's was gone some time ago.
His beard, on the other hand ... holy Christ. It's a thing filled with murderous intent. I'm sure it walks the nights alone, thirsting for blood while its owner is asleep.
Anyway, here's a YouTube video from back when Anthrax was still on top of their game, the appropriately named: Among the Living.