Naiads have membranes between the fingers to swim easily. They spend most of the time in or near fresh water because a naiad which would stay on dry land for too long would dry up and could suffocate.
Nordlings consider their body type so attractive that an adage "to be as shapely as naiad" is used to describe beautiful young girls' physique. Aen Seidhe elves think similar, adorning palaces with marble statues of naiads.
Though usually silent, they are able to sing beautifully. They come out of the water at night to dance in the moonlight. Rusalkas are known to be afraid of humans, thus only a few have ever seen one.
They are said to lure men with their beautiful songs and then drown them. Other tales tell of them dancing men to the point of exhaustion and death. True or not, according to dwarves they were always savages and didn't care much for civilization.