The Clan of Blueblood witches is one of the witch clans on the continent of Erilea. They are apart of the Ironteeth Alliance to tear down the Crochan capital.
The Bluebloods are renowned for their devotion to the Three-Faced Goddess, and this piety is an integral part of life in the Blueblood Witch-Clan. They are somewhat reclusive, and spend much of their time performing rituals in honor of their deity. Only the blood of specific types of humans, such as virgins, may be drunk by Bluebloods.
The Blueblood Matron wears a band of barbed iron stars across her forehead. This is because the Bluebloods purportedly have such strong ties to magic and the Three-Faced Goddess that the Blueblood Matron needs more iron than most witches to keep her anchored to this world. In place of the iron crown, the Blueblood heir dons a leather band instead. By tradition, the Matron's robes are deep blue.
This fierce dedication sometimes presents itself as arrogance. For instance, in Heir of Fire, Manon remarks with disdain that the Bluebloods arrived at the Omega first and claimed the highest rooms "because they needed the mountain breeze to complete their rituals"; Mother Blackbeak calls the Bluebloods "religious fanatics with their noses in the wind".
Five centuries ago, the Blueblood witches had a vision of the Witch Kingdom under Ironteeth rule. They were the ones that had mustered the Clans to fight against the Crochans.
According to the authors Pinterest, they do resemble humans and don't possess metal teeth.