Giant Raven

A Giant Raven is a large black bird that comes if evil is on its way.

SPOILERS BELOW

In the second story, a Giant Raven is seen, and Frost explains to Storm what it means. This bird foreshadows that a traitor (Stone) would rise and was warning them because they were the only ones that could do anything about it. Of course, Frost attacks it and it leaves, but it leaves and doesn't fight back only because it knows its message had gone through to them.

SPOILERS ENDED