Wait one cotton-picking minute!
"Cotton-picking" is an Americanism originally used in the early 1900s to refer to a contemptible person. This probably comes from the fact that before the machines took over most of the work, cotton picking was one of the most laborious chores on a plantation. Related to this, cottonpicker was a derogatory term for a black person back in the 1930s.
The modern use of the phrase derives almost entirely from Bugs Bunny, first appearing in a 1952 cartoon in which he exclaims "Get your cotton-pickin’ hooks offa me!" This introduced the term to a generation of impressionable youngsters, and these days 'cotton-picking' is seen as silly and a bit old-fashioned, but it is not generally viewed as racist or otherwise negative.