A 2015 Lincoln cent, it's called the Shield cent for obvious reasons. You've never seen one of those before ?!?
It is called Environmental Damage.. Toning, exposure to the elements, chemical stain, human contact. All these will alter the color of a Copper coated zinc planchet.
I think he forgot to log into his alt account before answering himself. I have me theories but will keep them to myself for now.