The wide variety of descriptions in the Aswang stories make 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 in meat processing professions by day. As regular townspeople, they are quiet, shy and elusive. At night, they transform into creatures that 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 or their homes. Some also make noises, which are louder the further away the Aswang is, done to confuse its potential victim. They may also replace their live victims or stolen cadavers with facsimiles made from tree trunks or other plant materials. This facsimile will return to the victim’s home, only to become sick and 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.
A type of Aswang, the Kikik/Tik-Tik, turns into a enormous, prowling bat or bird at night, looking for pregnant women. As it sucks the blood from the fetus with its long proboscis, it makes a ‘kik-kik-kik’ sound. Other stories relate the kikik as an Aswang’s familiar, its sound masking the Aswang’s proximity from would-be victims.
The term wak-wak or wuk-wuk is frequently used for the same creature in the Cebu region. The legends of the wak-wak and kikik are much the same, but the wak-wak is specifically supposed to change into its birdlike form by leaving behind its lower body, much like the Manananggal. The cry of a night bird which makes a “wuk-wuk-wuk” sound is believed to be the call of this monster and is feared by superstitious villagers. As with the call of the kikik, the wak-wak is believed able to make its cry sound distant when the creature is near.
The sigbin or zegben has been known as another type of Aswang, and alternately, as the kikik’s familiar. Its appearance is said to be similar to the chupacabra and the Tasmanian devil, although with spotty fur, wide mouth with large fangs.
One of the most popular legends in the Visayas region is the infamous Aswang Tiniente Gimo or Lieutenant Gimo from Dueñas, Iloilo. In addition, The most commonly known in terms is something called Tyanak/ Tianak happens to be as the unborn baby’s due abortion.
Typically, an Aswang is revealed by using a bottle of a special oil extracted from boiled and decanted coconut meat and mixed with certain plant stems upon which special prayers being said. When an Aswang comes near or roams around the house at night, the oil is said to boil (or froth into bubbles) and continue boiling until the Aswang departs.
Buntot pagi or stingray’s tails, shiny, sterling silver swords, and images of old crones or grandmothers have been said to dispel their presence. The myth of silver weapons warding off evil creatures is probably taken from western mythology.
Throwing salt at Aswangs is also said to cause their skin to burn. This belief may stem from the purifying powers attributed to salt crystals by various traditions of witchcraft.