Lesson 4: Human Transfiguration.

Human Transfiguration is a branch of Transfiguration in which one Transfigures human body parts or an entire human being into another form. This can be considered a difficult branch of transfiguration because it is more powerful than turning an object into another object.
Human Transfiguration can be used to essentially replicate the natural abilities of Metamorphmagi, allowing the practitioner or the subject to take on an entirely different form, or make various individual changes to their appearance, such as growing or changing the color of one’s hair or taking on individual animal body parts.
However, while human Transfiguration can presumably be performed by any wizard who’s skilled enough, on themselves as well as on others, a Metamorphmagus is born with the ability to make such changes to their own bodies with little to no effort, and without the use of a wand.
Although it is possible to Transfigure humans into inanimate objects, it is unknown how someone someone Self-Transfiguring into an object would be able to Untransfigure without the intervention of another witch or wizard.