Yesterday while cleaning the coop and run, changing water, freshening feed, collecting eggs, etc I found this really tiny egg (it's definitely from one of mine). I took a pic for size comparison next to one of my other girls' eggs. Then my son's home support worker cracked it open so I could take pics. It was complete with the tiniest yolk and whites.
It's a fart egg with a tiny yolk. Most often they just have the white but every once in a great while they will have a tiny yolk too.