http://www.peddygist.com/2016/05/photosteenager-has-unborn-twin-who-had.html
According to local media reports, the foetus had hair, legs, hands and genitals.
Mohd Zul Shahril Saidin, 15, had been carrying the foetus since birth - a condition known medically as 'foetus in foetu'.

The boy's mother, Hasmah Ahmad, expressed her relief to local media after surgeons in the north-
western Malaysian state of Kedah performed the successful operation.


Mrs Ahmad, 38, described the mass in shocking detail, saying:
'The foetus removed from my son's stomach was formed with organs like those of a baby – only the nose and mouth were not complete.'
The teenager was only hospitalised recently after he began complaining of pain over the last four months. Mrs Ahmad said she and her family had already performed funeral rites on the foetus, which is now buried in a cemetery.

Her son is still recovering in hospital.

It is estimated that 'foetus in foetu' occurs in 1 in every 500,000 live births.
During the early stages of pregnancy, if a woman is pregnant with twins, one of the babies can enter the other through the umbilical cord. There, it becomes a parasite, depending on its sibling's body for survival.
See more at: http://www.peddygist.com/2016/05/photosteenager-has-unborn-twin-who-had.html
Usually, it does not survive after birth, but can be life-threatening for the baby that does survive.

strange

Medically- it is called fetus in fetus
Traditionally- witch implanted blood sucker.