An Animagus was a wizard who could transform into a particular animal while retaining their magical abilities. It was the pinnacle of Human Transfiguration.
An Animagus's animal form was usually related to their personality and body weight, and the animal was always a Non-Magical Creature.
The process was extraordinarily complicated and dangerous, involving several fields. For one full month, from full moon to full moon, the wizard had to keep a single Mandrake leaf in their mouth at all times.
They could neither swallow the leaf nor take it out. If it left their mouth at any point, they had to start over.
At the full moon, they had to remove the leaf and place it in a small crystal vial filled with their saliva, then leave it to absorb pure moonlight. If clouds covered the sky that night, they would need a new Mandrake leaf and have to start over.
To the moonlit vial, they had to add one of their hairs and a silver teaspoon of dew collected from a place untouched by sunlight or humans for seven full days.
Finally, they had to add a Death's-head Hawkmoth Pupa. The mixture had to be kept somewhere quiet and dark, neither looked at nor disturbed until the next thunderstorm arrived.
While waiting for the storm, they had to perform the following action at every sunrise and sunset: point the tip of their Wand at their heart and recite, "Amado, Animo, Animado, Animagus."
The wait for a thunderstorm could last weeks, months, or even years.
Throughout that time, the crystal vial had to remain completely undisturbed and out of the sun. Contamination by sunlight would cause the most disastrous mutations.
If they continued reciting the incantation at every sunrise and sunset, a moment would come when they felt a second