City slicker maybe. You mean a negative expression used by people in the countryside?

Over the years I have heard townie being used but not that often.

City slicker can be negative or neutral, depending on the tone and context. Bumpkin, for its part, is normally negative. As a person who has spent much of his life in two of the 10 largest metro areas in the U.S., but is now on a work assignment in an isolated college town that’s 5 hours from the nearest (non top-10) major city, I usually call myself a “city boy”. I don’t mean “city boy” to be negative—just descriptive and maybe a little funny. That said, I tend to think that some of the country people here, who love their country lives, take it negatively....

Around here we'd use "city boy" which is from midly condecending to insulting. For ex the ones moving to our little town or area and panic when they hear a story about a coyote or hear gun shots. Two things anyone from here won't give much thought to.