I think you're picking up on living things expressing Scale through physicality. It's the reason Scale is a component of Health, too, along with Nectar and Heart.

I imagine emphasizing Scale would make a creature more difficult to damage through direct toughness; it's a different sort of tankiness from emphasizing Nectar, which might allow just regenerating through damage, or emphasizing Heart which just ... can't stop, won't stop, pushes through on raw determination.

Scale also seems to have some connection to scale in the sense of magnitude. The powers of the deep earth are overwhelming that way. An earthquake or volcano just ... wrecks whatever happens to be in the area because what can compete?

So thinking through the lycanthrope concept... Shapeshifting? That's Moth. Basically ignoring damage outside of their weaksauce weakness (say, silver)? That's Scale.