Rampaging amped-up Type A-minus personalities.
Give a person a few too many decades of life and first they get cranky, then they figure they have to retire somewhere warm and cheap and annoy people.
Suddenly they are fabulously wealthy on an $800 pension and damn well want everyone to know who the new boss is.
First they hire a maid, then a gardener, and possibly a cook, all to help with work in a one-bedroom cottage with no yard and nothing going on.
Free-floating hostility is a distinguishing characteristic. Any little old thing will set off one of these yokels. Some common causes of temper tantrums in stores, banks, and cafes are being delayed more than one second, getting confused due to deafness in one ear and poor hearing in the other, and not understanding anything because of refusing to learn the language.
Meanwhile, they feed off the goodness of the locals while complaining that those same people are all worthless thieves and idiots.