All animals have the traits of a certain type of mammal. The extent of these traits varies depending on the individual, from being limited to the ears and tail (e.g. Dog Girl, most kitsunes) through to the entire lower body (e.g. Centaur Girls, who have the lower bodies of horses). Kitsunes follow this pattern except that they also have multiple tails (ranging from two to nine in number), with the number of tails being proportional to the power of the kitsune.
Most beasts are strong and quick, but their defense (especially to pleasure attacks) is weak. In contrast, kitsunes are skilled with magic, with a particular focus on the earth element.