What is this flag?

[Shadow Wolf]

Also, people lived on Ireland for a long time before this mysterious tribe that claimed to descend from two of the animals assigned to Dan, which has Dan (Dana) as the meaning of the tribe and "the people of Dana" in title.

Yes. The earliest inhabitants wsre there before the last Ice Age. That came along, the islands were abandoned, the ice went away, and for various reasons stretching a chunk of our specie's history people moved westward, the Celts rose and declined, and moved further westward. Rome and a handful of Germanic tribes shaped things regarding Briton and Ireland more than the Jews did.