Hippie
You really don't have to scale the gamut with this everything goes costume. Shower and shave optional, with the functionality of getting high on all sorts of drugs to enhance your roll. I wonder why I haven't seen more metal heads embrace this one, it's almost too easy.
Well there you have it, 5 simple long hair ideas to get those wheels spinning. I personally prefer variations of zombie costumes, especially because it allows me to toy with foam latex prosthetics, but it requires several hours of prep time and lots of patience. Zombie like creatures and prosthetics also work better with short hair and less facial hair due to the use of spirit gum, if that fits your description then your gold!
The idea here is to promote some fun with your night, we all know that guy who shows up to a costume party in his usual Tuesday thread, what a lame ass. If you have more ideas for cool metal head costumes, bring it! We'll be reading your comments below, let's hear some of your ideas for this year's upcoming bash.