Update on my hen with horrifying egg. (Good news).
DH took her to the vet while I was at work on Tuesday. He took the nasty blob with him to show the vet plus some pictures of the egg. Annnnddddd the vet said she had never seen anything quite like it before

The whole staff wanted to see it after they put the blob under the microscope.
Good news though they gave Buttercup a very thorough exam. Checked every inch of her from comb to toes, even down her throat and up the hoo-haa. They also had her walk around the room to check her movement, checked her poop, took her temp and heart rate. She seems perfectly healthy!

They think the egg was basically a glitch. They had a longer way of explaining it that DH did his best to relay to me....but basically, as long as she doesn’t develop additional symptoms, they think it will be just a one time thing).
She has laid 2 eggs since the incident. It is the first time in a month or two that she laid two days in a row, and I think maybe the increased laying is a good sign? And the eggs themselves look alright. The first one had a small meat spot and some shell issues, but yesterday’s looked pretty good!
Thank you squatchers for the love and support!