Metamorphmagi

A Metamorphmagus (plural: Metamorphmagi) is a witch or wizard who possesses the rare, innate magical ability to change their physical appearance at will, without the need for a wand, an incantation, or a potion like Polyjuice Potion. This ability is hereditary and cannot be learned. The most prominent example of a Metamorphmagus in the series is Nymphadora Tonks, a member of the Order of the Phoenix.

The core ability of a Metamorphmagus is to alter their physical form through sheer force of will. This powerful form of magic is demonstrated to have a wide range of applications, from minor cosmetic adjustments to significant changes in apparent age and features.

• Voluntary Changes: A Metamorphmagus can consciously alter their appearance. Nymphadora Tonks frequently changes her hair colour and style to suit her mood, from bubble-gum pink to violet. She also demonstrates the ability to change the shape of her facial features, such as altering her nose into that of a pig or an old woman to entertain Harry Potter and Hermione Granger. This skill is exceptionally useful for disguise, and Tonks noted that she achieved top marks in Concealment and Disguise during her Auror training without needing to study.
• Involuntary Changes: The appearance of a Metamorphmagus can also be linked to their emotional state. Strong emotions can trigger involuntary changes. For example, Tonks's hair often reflects her mood, turning a shocking pink when she is happy or a fiery red when she is angry.
• Impairment of Ability: Extreme emotional distress, such as depression or grief, can significantly impair or suppress a Metamorphmagus's abilities. After Lord Voldemort's return was made public and while she was struggling with her feelings for Remus Lupin, Tonks found it difficult to control her transformations. Her hair remained a mousy brown, and she appeared pale and ill. Her despair also caused her Patronus to change form.

The ability to be a Metamorphmagus is not a skill that can be acquired through study; one must be born with it. It is an extremely rare, hereditary trait passed down through bloodlines.

• Nymphadora Tonks: The primary example in the series, who inherited the ability.
• Edward Lupin (Teddy): The son of Nymphadora Tonks and Remus Lupin. He inherited his mother's ability, as his hair was observed changing from black to ginger to blue shortly after his birth.

The unique nature of a Metamorphmagus is best understood by contrasting it with other forms of magical transformation.

• Animagi: An Animagus is a witch or wizard who has learned the complex magic of transforming into a single, specific animal. This is a learned skill, not an innate one, and is limited to one non-human form. Metamorphmagi, conversely, are born with their ability and can alter their human appearance in various ways, but are not shown to be able to take on an animal form.
• Transfiguration: General Transfiguration is a broad branch of magic that uses spells to alter the form and appearance of objects and living beings. These transformations typically require a wand, an incantation, and a high degree of skill. A Metamorphmagus's ability is internal and wandless.
• Polyjuice Potion: The Polyjuice Potion is a difficult-to-brew concoction that allows the drinker to assume the physical form of another specific person for a limited time. It requires a part of the person being copied (e.g., a hair) and its effects are temporary.

The word “Metamorphmagus” is a compound term derived from Greek and Latin roots.

• Meta-: A Greek prefix meaning “change,” “after,” or “beyond.”
• Morphē (μόρφος): A Greek word meaning “form” or “shape.”
• Magus: A Latin word for “wizard” or “magician.”

When combined, the term literally translates to “change-form-wizard” or “a wizard who changes form,” accurately describing the ability.

J.K. Rowling has confirmed that the ability of a Metamorphmagus is an inherited trait that cannot be learned. She described it as a “very rare” magical gift. (Pottermore) In the film adaptation of Harry Potter and the Order of the Phoenix, Tonks's ability is showcased with rapid visual effects, particularly in her introductory scene at Number Four, Privet Drive. (film)