"Do not cut the hair at the sides of your head or clip off the edges of your beard." (Leviticus 19:27)
Thus, a true Christian is not clean shaven, or have a crew-cut hairdo. In fact, if they want to cut their hair, they can only cut the front and the back. Which would look very weird...sort of like a reverse mullet, short on the sides, long in front and back.
Now, Satanists are just Christians who turn everything upside down. Which means that the most SATANIC hairstyle is...The Mullet! So if you see someone who is clean shaven and sporting a mullet, run, for they may be the Anti-Christ!!!!!!!
ttyl