Do we have any background info on The Children and The Architect Under The Tree from previous episodes? For example, anyone know if they are mentioned in any of the prayers to the Old Gods? I can't google this, I know I'll get spoiled.

I hope that happens. A dragon on the loose and bran being told he's gonna fly, both in the same episode. This has to go somewhere!
I'd be super disappointed if the dragon just eats more village kids in Mereen and all Bran gets is more bird's (third) eye view.