An Aswang (or Asuwang) is a shapeshifting monster in Filipino folklore usually possessing a combination of the traits of either a vampire, a ghoul, a warlock/witch, or different species of werebeast, or even all of them together. It is the subject of a wide variety of myths and stories. Spanish colonists noted that the Aswang was the most feared among the mythical creatures of the Philippines, even in the 16th century.
The myth of the aswang is well known throughout the Philippines. It is especially popular in the Visayas, southern parts of Luzon, and parts of Mindanao. Other regional names for the aswang include "tik-tik", "bayot", "wak-wak", "sok-sok" and "kling-kling".
Aswang or "asuwang" is derived from the Sanskrit word Asura which means 'demon'.
Sometimes this creature is called the "bal-bal" or ghoul (maninilong in Catanauan, Quezon), which replaces the cadaver with banana tree trunks after consumption. Aswang stories and definitions vary greatly from region to region and person to person, and no particular set of characteristics can be ascribed to the term. However, the term is mostly used interchangeably with manananggal and are also usually depicted as female.
The wide variety of descriptions in the aswang stories makes it difficult to settle upon a fixed definition of aswang appearances or activities. However, several common themes that differentiate aswangs from other mythological creatures do emerge: Aswangs are shape-shifters. Stories recount aswangs living as regular townspeople. As regular townspeople, they are quiet, shy and elusive. At night, they transform into creatures such as a bat, bird (usually an eagle or hawk), boar, cat, or most often, a dog.
They enjoy eating unborn fetuses and small children, favoring livers and hearts. Some have long proboscises, which they use to suck the children out of their mothers' wombs when they are sleeping in their homes. Some are so thin that they can hide themselves behind a bamboo post. They are fast and silent. Some also make noises, like the Tik-Tik, (the name was derived from the sound it produces) which are louder the farther away the aswang is, to confuse its potential victim; and the Bubuu, an aggressive kind of aswang that makes a sound of a laying hen at midnight. They may also replace their live victims or stolen cadavers with doppelgangers made from tree trunks or other plant materials. This facsimile will return to the victim's home, only to become extremely sick and then die. An aswang will also have bloodshot eyes, the result of staying up all night searching for houses where wakes are held to steal the bodies.
Aswangs are physically much more like humans at daytime; they only change their appearance at night when they feel they are in need of food. It has been said that if an aswang married a human, upon their wedding, his or her mate would become an aswang as well but rarely can they reproduce. The couple may hunt together at night but will go in separate directions, either to avoid quick detection or because they do not like to share their food.
Unlike vampires and other similar creatures, they are not harmed by sunlight. They are daywalkers. Aswangs can also be befriended, they can talk to you like any normal human: they laugh and/or cry, get angry/sad, get hurt/humiliated and feel scared and envious. These creatures do not harm their friends and neighbors, and were said to be exempted from their target victims for food, hence the Filipino saying, "Mas mabuti ang aswang kaysa sa isang magnanakaw" (English: "Better an aswang than a thief").
They search for food in faraway places that it would not be too obvious for them. Aswangs are said to be vulnerable during daytime because during that time they do not have the excessive superhuman strength that they have in their nighttime prowl (aswangs only transform at night because they believe that God is dead or sleeping). When people know of their identity, they are hunted down and killed immediately.
Like vampires, aswangs are repelled or killed by using garlic, salt and religious artifacts/weapons (e.g. Holy water, crucifix, rosary, prayers and religious verses). They are also killed using a whip made entirely of a stingray's tail (buntot pagi), which may also be used to repel the creature (aswangs are said to be scared of the sound made by the whip's cord slashing through the air). It is also said that they cannot step on holy consecrated ground (i.e. churches, mosques, temples, etc.). Decapitation is also a way to destroy an aswang.
Certain agimats (native Philippine amulets) and special prayers posted on doors and entrances may also repel aswangs. A good example of which is the red and black bead bracelets worn by newborn babies.
It is said that to spot an aswang at daytime, look straight at their eyes. The person in front of you is an aswang if your reflection is upside-down. Another way of knowing is looking in a tuwad manner; that is, bending over and looking at the person from between your legs, upside-down. The person is an aswang if the image of the person is different. It is said that a person without a philtrum is an aswang. Hintura (Iloilo) is a kind of oil made by albularyos is used to detect if an aswang is near the premises. It is said that the oil will boil and bubble if an aswang is near.The Aswang is the subject of the 2011 feature-length documentary The Aswang Phenomenon. The film explores the aswang folklore and its effects on Philippine society. The documentary was also the first to uncover the origin of why the Western Visayan province of Capiz is suspected as the aswang's home.