Ok, so it's been hinted in the Meet the Exiles video where the southern bell refused to even talk about, assuming it's something creepy. Also judging by this picture: It sustains itself in a gaseous pod, as well as a syringe? Sounds gross, but I don't have to deal with them as roommates being Dominion. Furthermore, if you take a look at this!: On the far left. A freaking zombie hand! You see the bone and stitches. All four of these hands most likely represent the four races that form the Exiles! So if you put the pieces together, the fourth race might be a mutant zombie that sustains its longevity with pods and chemicals!