Parasitic twin

Okay, so imagine you have a friend who comes to visit you, but they are actually two people stuck together. It's like they are glued together and can't be separated. One of them is a full person with all the normal body parts like the head, eyes, arms, legs, and all the important organs like the heart, lungs, and stomach. The other one is like a smaller version of them, but it doesn't have all the body parts it needs to live on its own. It's kind of like a baby, but not really.

The smaller one is called the parasitic twin because it can't survive on its own and needs the bigger twin to stay alive. Sometimes the bigger twin can even live a normal life without even realizing they have a parasitic twin attached to them. But other times, the parasitic twin can cause problems for the bigger twin, like if it's putting pressure on their important organs or causing them pain.

Some people with a parasitic twin might need surgery to have it removed. In some cases, doctors can even separate the two people so they can live separate lives. But sometimes it's not possible to separate them, so they will always have to live together.

So basically, a parasitic twin is like having two people stuck together where one is a full person and the other is like a mini person that needs the bigger person to survive.