The Matruculan is one of many Filipino creatures who attack pregnant women. This particular creature first impregnates a virgin before coming back later to kill the woman and eat the fetus (although some stories say that both mom and baby are eaten). Some stories claim that the woman is not a virgin but rather married and already pregnant.
To protect the mother and child, the husband must swing a balisong (knife pictured below), or butterfly knife, above the woman’s belly while she is in labor.
This leads one to wonder: which is scarier, an invisible mythological creature, or the father of your unborn child brandishing a knife above your abdomen?