What is "batibat"

The Batibat or Bangungot is a vengeful demon found in Ilocano folklore. These demons were blamed as the cause of the fatal nocturnal disease called bangungot. A batibat takes the form of a huge, old, fat woman that resides in trees. They usually come in contact with humans when the tree that they reside in is felled and made into a support post for a house. This causes them to migrate into holes found in the post. The batibat forbids humans from sleeping near its post. When a person does sleep near it, the batibat transforms to its true form and attacks that person. It sits upon the chest of its victim until he suffocates. To ward off the batibat, one should bite one's thumb or wiggle one's toes. In this way, the person will awaken from the nightmare induced by the batibat.