A Mullet is a hair style - short on top, long in back. It was in 'vogue' in the 1980's (IIRC). Now it's usually sported by the dregs of society ... aka losers.
And I know he has one from his appearance on TV. When I saw his 'mullet', I thought "oh-oh, bad sign."
Case in point, here's three of your 'average' Mullet wearers...
Would you want this type of guy dating your daughter, niece, grand-daughter? And the gang-banger is really impressive isn't he.
(why people put there pics on the net amazes me)