Hot bag of nickels
to describe a ugly person either male of female.
"Mary looks like she got hit with a hot bag of nickels"
Hot bag of Nickels
When one takes nickles and boils them in water and then places them in a bag of sorts, such as a tube sock. When beating a person with a hot bag of nickels no bruising will occur no matter how hard you hit them as long as the nickels stay warm.
When my kids get on my nerves I simply beat them about the face and neck with a hot bag of nickels because it will not leave a mark.