I have looked at other odd eggs on the internet but have not seen one quite like this. There are pictures of eggs with one egg formed inside the other, one shaped like a shoe, one with a tail but none with seams.
This must have been two eggs that hooked together.
Of course when I cracked it it held two yolkes. One with lots of white and one with not so much white. Very odd but very delicious. I made bacon and egg quesadillias with them. Yummy!