The Cult of the Third Moon is a fictional organization in the Marvel universe which first appeared in 1998 in issue #1 of the 2nd volume of the Werewolf by Night comic book series.
The Cult of the Third Moon was founded sometime before the birth of Christ. it's a cult with a mysterious origin and history. During the Middle Ages they attempted to gain control of Varcolac via the Wolfsblade. They failed and became indebted to Varcolac. The murderous cult performed human sacrifices to Varcolac, as recently as the late 20th century.