THANE, INDIA — Doctors in India got the shock of their lives after discovering a newborn baby boy was carrying with his own twin brother. <br /> <br />The anomaly was detected by a radiologist, who found a 7cm-long mass during an ultrasound of the then-pregnant 19-year-old mother, the Mumbai Mirror reported. <br /> <br />When the baby was born days later, another scan revealed that the mass behind the newborn’s stomach contained a small fetus with a tiny brain, head, and limbs. <br /> <br />The rare abnormality is called fetus in fetu, and occurs when one fetus wraps around and envelops the other, while still sharing a single placenta. The enveloped fetus lives on inside its sibling, feeding off like a kind of parasite. <br /> <br />It can get implanted in the neck, the tailbone, sometimes even the skull. <br /> <br />The host baby can also die if continuously robbed of nutrition, but in this case, surgeons intervened and successfully extracted the parasitic twin. <br /> <br />The baby is recovering, and will have a great story to tell once he gets older.