By the 19th century Jacob Grimm mentions the Nixie to be among the "water-sprites" who love music, song and dancing, and says "Like the sirens, the Nixie by her song draws listening youth to herself, and then into the deep." According to Grimm, they can appear human but have the barest hint of animal features: the nix had "a slit ear", and the Nixie "a wet skirt". Grimm thinks these could symbolise they are "higher beings" who could shapeshift to animal form.