The prototype

Body and size: It is much larger than ordinary toys, with a humanoid but stylized body, like a perfectly proportioned doll. It is not excessively monstrous, but rather gives a sense of "disturbing perfection."
Head and face: It has classic doll-like features, with a fixed smile that gives it a terrifying air and bright, almost lifelike eyes with a piercing yellow glow. Its facial expression can change slightly depending on the light or perspective, creating a sense of tension.
Arms and hands: They are long and articulated, with defined fingers that seem capable of grasping or manipulating with precision. This gives it a more sinister look as it moves around the factory.
Color and texture: The prototype's skin is smooth and uniform, with an almost plastic finish, but with details reminiscent of a high-quality doll. It's generally in light or pastel tones, which contrasts with its intimidating gaze.
Movement: It moves smoothly and silently, much more agile than normal toys, which makes it particularly threatening when it appears out of nowhere.
Aura: Its design is intended to generate both fascination and fear; it's elegant, flawless, but with a disturbing air. As if it were "too perfect to be an ordinary toy."

Calculated and methodical: Unlike other more chaotic enemies like Huggy Wuggy, the prototype seems to plan every move. It doesn't launch an attack impulsively, but moves precisely and deliberately.
Imposing yet silent: It makes no unnecessary noise. Its presence creates tension because you know it's there before you see it, thanks to the feeling that "it's watching you."
Attractive and disturbing: It has an almost charming, elegant air that slightly deceives the player. Its "perfect" design sparks curiosity, but its yellow eyes and fixed smile reveal that something is wrong.
Disturbing patience: It doesn't despair; it can wait and stalk, like a patient predator. This makes it all the more terrifying.
Devoid of visible human emotions: Unlike other characters, he displays no "human" fear, joy, or anger. His face and movements convey efficiency and menace, rather than feelings.
Mysterious: We still don't know much about its true motivation. It seems as though it was created to fulfill a specific purpose in the factory, probably related to supervising, testing, or controlling the toys.