I worked at my uncle's diner for a summer a few years back, and I honestly have never encountered such a prick as the one from this story I'm about to tell.
He was middle-aged, obviously southern from his accent, and apparently couldn't read for shit despite the grapefruit sized glasses he was wearing. I wound up being this asshole's waiter and having to cater to his needs, his wife's (who I will admit was surprisingly well behaved all things considered) needs, and their screaming three year old (guessing) child's needs. On the menu there's basically a rounded breakfast, that consisted of eggs (however you asked for them, sunny side up, runny, scrambled, so on and so forth), toast, grits, and a side of sausages. When it came time to pay the bill, he refused to pay for what he ordered (the aforementioned breakfast), because it came with a side of sausage that "he didn't order". After I pointed out it was in fact what he ordered and that the sausage came with it, he still refused, saying "that's not what I ordered", despite the fact that he had asked for it by name, and what was written on the ticket confirmed it. Twenty minutes of arguing and one threat to call the cops later, he finally paid his bill, and left with his wife and child (who I would like to point out, never stopped screaming).