One of my EE's laid an egg that size. I couldn't believe something that size could come out of a chicken...OUCH! I was disappointed that it only had two yolks too...
I got an egg like this before. We cracked it and it had 2 yolks in it. We still have it in a ziploc container. But sadly it was too much for the hen that laid it cause she died 2 days later.