Renny is the mother (and father) of all dragons. Long ago, all the other dragons were slain, leaving Renny alone in the world. She repopulated the world, giving rise to the current family of dragons that rule the world. She doesn't have a separate priesthood. Her family rank is the rank of her religion. Not all dragons worship Renny as a god, but all dragons have a place in the family hierarchy, defined by their distance from Renny in the family tree.

Rank 0 - Dragonblooded
Rank 1 - Half-Dragons
Rank 2 - Distant Full Dragons
Rank 3 - Great-Great-Great-Grandchildren
Rank 4 - Great-Great-Grandchildren
Rank 5 - Great-Grandchildren
Rank 6 - Grandchildren (the rulers in the mountains)
Rank 7 - Renny's Children
Rank 8 - Renny