I have been on this forum off and on for over ten years. During that time, I have seen all kinds of wood, cloth, countertop material, and lots of different books, papers, and other materials used as backgrounds. Also plenty of fingers and palms. I don't ever recall seeing a bare leg being used as a background until recently, and now I have seen two in just a little over a week. Must be a new trend.
Welcome to the forum, Ashley.
As others have stated, your coin was subjected to a corrosive environment, which "ate" the copper core more than the copper/nickel cladding. The is why the edge looks like it has a groove around it. I don't see any errors, and it is in pretty bad shape. It isn't rare, and it isn't valuable - just worth 25 cents.
It is, however interesting looking. I would keep it for just that reason, but if you choose to spend it, no harm done.