Conjoined Twins
You probably know what conjoined twins are! They are twins who are connected to one another. This happens when a fertilized egg does not part all the way. This often happens when the split takes place 12 days or more after fertilization. Others, however, believe that the egg had already divided but fused back later on. The fusion is often seen in the abdomen or chest and varies. However, the twins typically share a vital organ or more. Sadly, they typically die in the womb or shortly after delivery. It is possible to separate the ones who survive, although it depends on where and how they are joined. Even though they share certain body parts, they are two individuals who can think for themselves.