There's no question, that's an eggceptional breakfast.
YouTube user Sean Wilson's video in which he cracks a 6-ounce egg has been viewed half a million times. Wilson says the egg measures almost 10 inches around and it came from his chicken. He weighs the egg on camera and compares it visually to normal eggs, then prepares to crack it for a sandwich. To his amazement, one yolk pops out along with another full egg in a shell.
He's flabbergasted by the discovery.
New Scientist dedicated a video to explaining this rare phenomenon a few years ago. The curator of the Natural History Museum's egg collection (it's real) said it can happen when an egg is trying to make its break to the outside world. The egg descends the oviduct as it develops. However, if a chicken has abnormal contractions that push the egg back up the oviduct, another egg can develop around the first and voila — you have a neatly packaged double omelette.
I suspect the surprise is less pleasant for the chicken.