Asking a dh'lann if they are a man or a woman will give you at best a temporary answer. They spend most of their time as neither, or as potentially one or the other. Then, once a moon (and yes, there is a Moon Below), they change and transition into a gender. They don't know which gender ahead of time, and a parent might be a father of one child and mother of another.
While this makes their family structures interesting, dh'lann are as human as you or I. More so, perhaps. I have heard rumors of a mental power they share, but they will not speak of this openly.
In any case they are often receptive to the Truth, and our order has had an even greater impact on them then on the alien slithik. If only we had a secure way for the dh'lann to travel to the surface of the Ninth World, I believe we would have dh'lann training as Aeon Priests in no time.
– Charis Kos, Aeon Priest
More information on dh'lann will be found in the upcoming adventure: The Sun Below: City on the Edge.
Reece Ambrose is the Lead Artist for The Sun Below: City on the Edge, and his work can be found in many other games, including The Strange™, from Monte Cook Games.
I changed the name from flann after I got feedback from the gaming community that they sounded like custard.