Shapeshifting is the ability of werewolves and hybrids to change one's shape. More specifically, into a supernatural wolf. To werewolves, this power is activated involuntarily every Full Moon unless they develop it by wearing Moonlight Rings or evolving. For hybrids, this power can be activated at will.
During a full moon, they will unwillingly transform from their human form into their wolf form. However, if a female werewolf is pregnant, they will not turn for nine months as the transformation would kill the baby. There are ways to induce this trait outside of the Moon's influence. Such ways would be to become a Hybrid, through the possession of a Moonlight Ring or performing a unification ceremony. These three are so far the only known methods of voluntarily controlling a Werewolf's transformed state.
Non-original Hybrids and Klaus have the ability to transform into their werewolf forms at will. Most of them avoid transforming at all due to the pain it causes.
They still, however, have no control of their actions in werewolf form. They can also perform partial transformations, manifesting single features of their werewolf forms.
Elijah informs Klaus that he remained a werewolf for 2 days, even when the sun was up. Showing that a non-original Hybrid and Klaus can stay in Werewolf form longer than a normal Werewolf.
As seen with Klaus when he bit Katherine, a non-original hybrid and Klaus can transform partially, displaying their werewolf eyes and teeth. When a female werewolf is impregnated, they do not transform for nine months, or until the baby is born.
A kitsune may take on human form, an ability learned when it reaches a certain age - usually 100 years. As a common prerequisite for the transformation, the fox must place reeds, a broad leaf, or a skull over its head. Common forms assumed by kitsune include beautiful women, young girls, or elderly men. These shapes are not limited by the fox's age or gender, and a kitsune can duplicate the appearance of a specific person.
Foxes are particularly renowned for impersonating beautiful women. Common belief in medieval Japan was that any woman encountered alone, especially at dusk or night, could be a fox. In some stories, kitsune have difficulty hiding their tails when they take human form; looking for the tail, perhaps when the fox gets drunk or careless, is a common method of discerning the creature's true nature.
Variants on the theme have the kitsune retain other foxlike traits, such as a coating of fine hair, a fox-shaped shadow, or a reflection that shows its true form. Kitsune-gao or fox-faced refers to human females who have a narrow face with close-set eyes, thin eyebrows, and high cheekbones. Traditionally, this facial structure is considered attractive, and some tales ascribe it to foxes in human form. Kitsune have a fear and hatred of dogs even while in human form, and some become so rattled by the presence of dogs that they revert to the shape of a fox and flee. A particularly devout individual may be able to see through a fox's disguise automatically.
Werewolves are able to shapeshift from their human forms, to a half-human, half-wolf beast form at will. It is implied that werewolves are able to transform into "real" wolves as well.