Maybe because I have been the brunt of teasing all my life for being overweight that when I became the unofficial default leader of a department and because I have a very devilish and dry sense of humor, I was often the one to bestow nicknames on people. Most times I was very upfront with them about it, but there were a few times they were derogatory and only used behind their backs. I can't say I ever slipped, but I did hear others do so. A harsh factory environment can be a breeding ground for gallows humor, but will also build a high level of camaraderie. I always went by the theory that don't dish it out if you can't take it.
There was one press operator that couldn't have stood more than 4' 9" tall and was terrible at his job, I used to call him "half an operator." I heard a guy call him that and he heard it. He wasn't pleased.