Matruculan

Matruculan is like a combination of ghoul and vampires.  The creature is said to enter the house of a virgin and impregnates her.  After some time it will return inside the house and eat the fetus of the mother.  There is also a different version of the story where the creature enters the house of a pregnant woman and ripped her abdomen to extract the fetus and eat it, killing the mother in the process.  In an attempt to drive away the creature, the husband would slash the air with a balisong (folded knife) while their wife is having labor.  The belief in Matruculan can be traced back during the Spanish Era in the Philippines.

Matruculan is one of the few creatures who attack the pregnant women.  This creature would first impregnate the woman and eventually returns to eat the fetus.  Though in some legends, the mother and the fetus are both killed.  There are also other stories saying that the woman involved is not a virgin and that she has a husband and is already pregnant.  The slashing of air in order to protect a pregnant woman from the attack of the Matruculan is done above the belly of the mother while she is having a labor.  But one needs to be careful in brandishing a sharp knife above the abdomen of a laboring woman.