A double-yoker, I’ll wager.
I once had a Buff Orphington hen who would produce an oucher occasionally.
I got a double yolk in an egg just last week!.......storbought, too. I guess the candler was on break that minute...........
If it were allowed to hatch would the chick be exceptionally large also?
Or more, possibly. My parent’s friend gave them an egg her hen had laid. The laying of the egg killed the hen. I don’t know how much it weighed, but I’d wager it was quite a bit over four ounces. The egg was a quintuple (yes, five!) yolker.