"So that was it..." Su Er seemed to understand. When he opened his eyes, the figure in the mirror had become a black-and-white badger.
The reason Animagus Transformation required no wand was that it had already left an imprint within the body. As long as the wizard himself felt the desire to transform and used magic to activate that imprint, he could transform at any time.
Under the influence of magic, all the accessories on his body would also become special markings imprinted on his fur. For example-a wand.
This object, with its powerful magical properties, had to be set aside during the first Animagus transformation.
The reason was safety. During the first transformation, the wizard had to ensure that, apart from himself, there were no magical substances on his person that might affect the transformation process.
The amazing thing was that, once the first transformation had succeeded, he could subsequently transform with his wand under any circumstances.
(The original never said whether this was possible. Here, the setting is that it is not possible the first time, but is possible the second time and thereafter.)
Su Er stood upright before the mirror, marveling at his new appearance.
Black-and-white fur, bright, alert eyes, and furry, round ears.
Hmm, just as expected. Even as an animal, I was a handsome one.
He nodded in satisfaction, although having no wings and being unable to fly was a shortcoming.
"Ah... uh... ying..." Su Er opened his mouth and tried to speak. He clearly had a complete sentence in his head, yet all he could produce were a few single syllables.
There were his claws, too. Su Er extended the sharp claws hidden in his padded paws and casually swiped at the mirror frame.
Crash... clatter... The wooden frame supporting the mirror tore apart