Final answer:
Metal Fang is a fictional villain from Batman comics and is known for his distinctive features common to comic book villains, rather than real-life criminal behaviour. Factors like distinctive masks, usage of weapons, compelling backstories, and targeted victims define such characters within their stories.
Step-by-step explanation:
The serial killer Metal Fang is not a real-life criminal, but rather a fictional character known from the Batman comic books and movies. Since the question seems to be based on evaluating a killer from a work of fiction, it is probably best answered in the context of the character's impact within the story rather than real-life criminal behavior. In the case of Leatherface from The Texas Chainsaw Massacre, the effectiveness of a horror character may be judged on various factors including distinctive masks, use of poison, brutal methods, and targeting of specific victims.
However, since Metal Fang appears to be a character from a comic book series, they would likely be known for their distinctive features such as masks or costumes, unique weapons aligning with their character's theme, a compelling backstory explaining their behaviour, and how their actions induce fear or pose challenges to their adversaries like Batman. These characteristics help define the villain's role within the story, creating an engaging and menacing antagonist to the hero.