ugly customer

ugly customer

An ill-natured or vicious individual, as in Watch out for Charlie when he's drinking; he can be an ugly customer. This phrase uses ugly in the sense of "mean" or "dangerous." [c. 1800]
See also: customer, ugly
References in classic literature ?
To continue in fistic phraseology, he had a genius for coming up to the scratch, wherever and whatever it was, and proving himself an ugly customer.
But I guess Strickland was an ugly customer when he was roused," said Captain Nichols, reflectively.
The guide, which will help shed light on the lingo used in the world of strip clubs, includes BT, to describe a punter who is good to talk to, and See You Later, to describe an ugly customer.
The alternative, of course, is for referees, who are all aware of the noted "hit men," to get these ugly customers off the field with all dispatch should they step out of line.
NICE girls who hang around in bars can usually expect to attract some pretty ugly customers.
It being the Cold War, the United States was prepared, eager even, to make nice with all manner of ugly customers to combat the Marxist threat to the Western Hemisphere.
Terri has become a bit of an expert on snakebite first aid, which sounds like a good idea given her husband's penchant for getting up close and personal with some very ugly customers.