X-12 is a tall, human-like robot with white hair and blank mechanical gray eyes. While his physical appearance and strength would make him seem intimidating to most, his behavior and mannerisms suggest otherwise. His behavior shows that he has a gentle, almost childlike innocence that comes off as endearing. He's always eager to learn from every human interaction he encounters, and does his best to apply himself while fulfilling his desire to learn what it means to feel emotions as a human does.