A metal head is generally someone who enjoys metal. Trying to identify a metal head can be an easy task or a hard one. The life style the genre usually portrays is one of not caring and rebelling. Basically, do your own thing and fuck everyone else. This ties in with the whole "difficult" to identify because what you find as something unique, someone else may not. A metal head is stereotyped as a long haired, jean wearing fighter. While this may be true to some, it's not always the case (Except for the fighting aspect or at least the ability to harness an excess amount of rage and use it towards violenct.) Like the many different sub genres, I believe there are different types of metal heads.
The Physical Metal Head:
The easiest of the three to identy. Usually falls in with the "Long hair and denim jeans." stereotype. Exactly what the title states, their interest in the genre is shown physically. Whether it be through tattoos littered around there body, to hair grown down to their waist. More likely to attend concerts.
The Mental Metal Head:
This is the metal head you most likely will not be able to pick out of a crowd. Not ashamed to like the genre, instead he/she prefers the quieter approach to his undying love for it. This is most likely the quiet person with a few friends, usually also under the mental type. The Mental will more than likely commit a larger scale act of violence than a Physical simply because his rage is always bottled up until it can't be bottled up any longer. Usually hates people. Least likely to attend the concerts, but know more about the band then most.
The Mixed Metal Head:
Read the title. Mix random qualities from each of the above types and you've got yourself a molotov cocktail of ass kicking. Most people will probably find themselves associating with this title, simply because of the diversity of the genre and its fans.
There is nothing better or worse between the 3 types shown here, because in the end all 3 enjoy Metal and know that if you're a true Metal Head: No one gives a fuck about what type they are.
You probably could already tell, but I'm a metal head.