Raf Freire, an associate professor at Charles Sturt University's veterinary sciences school, explained to ABC: "To be honest, I don't really know how it's come about." He theorized that the chicken produced an egg normally but retained the egg from stress. The egg stayed put, and a second shell likely developed around both the first and second eggs.
"Biologically I'm struggling to understand why that smaller egg never dropped out," he said, "it's very odd."
Neither egg was eaten, so we'll never know for sure what blood-dimmed tide they would've unleashed -- or, you know, how they tasted.