Although they appeared mortal, they claimed lineage from Meru, a mystical mountain in India and supposed birthplace of the Arioi (what occult-scholars would later call the mythical Aryan race). Metal refused to cut their unblemished skin, while stone and wood forswore never to bruise them.
The bogatyri came into the Eldest's service when the Deluge washed a band of them against the Carpathians. In return for the Eldest's hospitality and-succor, they offered their allegiance. Each bogatyr possessed a skin pouch holding the flesh of the Antediluvian - when they fought for it, the skin pouch crawled over their faces and gave them the countenance of the Eldest.
Their forearm bones extended into blades, while their tongues darted out like daggers. When the Eldest fell to Samiel, the bogatyri scattered to the four winds to find it. They never returned, even after Yorak sent them messages that the Dracon had carried the Eldest to term.
Lambach Ruthven believes the bogatyri split and now guard the different manifestations of the Eldest.