"Messy" egg when opened?

[lizage]

I had an egg that looked larger then usual so I set it aside thinking it may have a double yolk. When I cracked it open over the weekend, the yolk was already all mixed up with the egg white and had a really strange consistency to it. Has anyone had this happen before? The egg was not shaken or mishandled prior to opening, but I've never seen anything like this before.

 

[TigerLilly]

Not me, but I'm curious to know whether it's ok to eat.

 

[Uzuri]

I've seen one or two, not many. I think it's a matter of them having a weak wall to the yolk.

I don't know what causes it or whether they should be eaten, though, either.