Sirens are a sub-type of Mariner (mer-cat) found on the water-world of Ashtoreth. They are distinctive in that they have large external translucent membranes that some describe as "wings", which serve as gills, making them amphibious, whereas Abyssianian Mariners merely have considerable lung capacity.

It is a common myth that Sirens are all female, but each clan of Sirens is ruled by a male of their species, a Triton. Relations between the Sirens and other species are most often violent, thus little is known about them or their culture.