Haircut or fish? The etymology of the word "mullet" has an air of mystery about it...
Interested? I recommend this article, which includes such gems as
"It might seem that mullethead "fool" came from mullethead "fish" (since the naming of human beings characterized by their behavior according to a metaphorical resemblance with animals is common). But mulletheaded "foolish" is recorded from 1857, seven years before mullethead "fish": "The men, for the most part sleepy, ignorant, mullet-headed looking wretches"; so it is not clear whether the fool was named for the fish, or the fish for the fool."
And--as promised, Melissa--I am including this:
I told you I had a girl-mullet. You didn't believe me, did you?