Neutral creatures in Heroes of Might and Magic V.

Have you seen the damage dealt by phoenixes?! It's simply enormous! By the way, I have a serious question. On Nival's official website, there's an explanation of all creature abilities. One of them is "Crystalline Scale." I quote: "The Crystal Dragon is immune to abilities that directly kill a creature, such as: 'Grasping Strike,' 'Cleaving Sword,' 'Accurate Shot,' etc."
A CRYSTAL DRAGON?! What is that?! Has anyone seen it in the game? Where is even one screenshot? An urgent explanation is needed!