Metamorphosis was a form of shapeshifting based not on species biology, but the Force. Through primitive magic or Force-imbued artifacts, a being could change its shape into that of another person, creature, or entity through the use of the Force.
Apart from the masquerade technique, metamorphosis was uncommon among Force-using traditions like the Jedi and the Sith, but not among the mysterious witches known as the Nightsisters of Dathomir, who utilized Talismans of Transformation and traditional Dathomiri illusions to metamorphose.
Charal metamorphoses to trap Cindel Towani.
On the planet Dathomir, Nightsister shamans were known to craft various Talismans of Transformation, rings or pendants enchanted through Allyan Magic to allow their wearer to metamorphose. Each of those talismans only allowed to turn into one specific creature by tapping into the energy of its "ur-spirit"—the single representative spirit for each species in the spiritual realm. The arcane powers of such artifact were a mystery to both Sith and Jedi scholars, who tried to explain their effects to no avail. The Nightsisters sometimes rode black stallions, which were also capable of shape-changing.
Charal, the self-appointed Witch-Queen of Endor, possessed such an enchanted ring, lost on Dathomir under Talzin's rule, which gave her the ability to turn into a raven. Charal was known to use it extensively, as she did during the Ewok–Sanyassan conflict of 3 ABY. On one such occasion, she transformed into a beautiful princess-like young woman in order to capture Cindel Towani. In this case, however, it is possible that her ring was not involved, so either she used traditional illusion, her cloak was Force-imbued, or she transformed through some other means.
The Ones, a family of extremely powerful and immortal entities who lived on the planet Mortis, wielded the ability to assume the appearance of virtually anyone or anything. One of them, the Son, would often turn into a winged gargoyle, but he once used the features of the late Shmi Skywalker Lars when confronting her son, the Jedi Knight Anakin Skywalker. Another member of the Ones, the Daughter, would assume the form of a large, luminous griffin. Similarly, the Force entity known as Abeloth was capable of stealing the physical appearances of beings that she had consumed.
Ros Lai's illusion-based transformation.
Sister Ros Lai, the biological daughter of Clan Mother Zalem, was known to use the art of illusion to project an image of herself as a deformed hag known as "the Rancor". She began transforming into the Rancor as a youth in order to avoid suspicion while plotting to avenge her dead father. When Lai stood away from her sisters' prying eyes, she would assume her natural form. Around 31 BBY, Jedi Knight Quinlan Vos arrived on Dathomir on a mission from the Jedi Council to stop Zalem from using a Star Temple's Infinity Wave against Coruscant, and witnessed Ros Lai's abilities at metamorphosis firsthand.
Another Nightsister stranded on planet Shira could use metamorphosis to take the shape of any being between 1.5 to 1.9 meters and 40 to 80 kilograms. She could retain this appearance for several hours.
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