Rusalye, also known as the Ice Dragon, was a sea whip found in the True Sea.
The creature is a legendary beast in Ravka folktales. Rusalye was believed to be a cursed dragon prince forced to take the form of a sea serpent and guard the frigid waters of the Bone Road. In children's stories, he would kidnap beautiful women and take them underwater. Once they died, he would sob over them and then go find others.