Parasitic Twins
As for parasitic twins, they are similar to conjoined twins but the smaller one depends on the bigger one for survival. Most of the time, the smaller twin is not fully formed or does not have certain vital organs. They form anywhere on the body of the bigger twin and appears as a small lump, a nonfunctional head, or additional limbs attached to the body. It could be a fetus in fetu, in which the parasitic twin forms inside the body of the bigger one. On the other hand, they might be acardiac twins. Twin to twin transfusion syndrome takes place when an identical twin receives too little blood flow, while the other gets too much. Acardiac twins go through a severe form of that, which involves the smaller twin being a torso with or without legs and a malformed or missing heart.
Parasitic Twins
