Caul

When a baby is born, it usually comes out of the mother's vagina. Sometimes, when the baby is born, there's a special thing that covers its head called the caul. It kind of looks like a sack or a hat made of skin. Some people believe that having a baby born with a caul is lucky or can even protect the baby from harm. It's not very common, but it's an interesting thing that can happen during a baby's birth!