Fear and Loathing in Athas
The Changelings are considered more of a myth then a reality. The majority of races treat them as a tale to tell their children to keep them in line thinking them nothing more then that. However in reality Changelings are more common than anyone knows.
They have become basically a Nomatic tribe, that as a cohesive unit travels the planes hunting and gathering, with scouts in every direction, allowing the "tribe as a whole to change to cause ease and comfort with any explorers they happen to encounter. This place also provides a safe haven for changelings to come and rest without having to worry about others, but the most important rule is no outsiders are to ever be brought there. If you seek shelter, you come alone, else you will be exiled from their socieity. ((unless you come with other changelings))
With this rule and society, changelings have been able to become a strong and plentiful race. There are those changelings who seek adventure, or a more stable life within the confines of the various city states, and they do well, just everyone needs a break, and it is nice to have a real “Home”.