In Vampire: Undeath, the true nature of a vampire is their Predatorial Nature. described as the "inner demon." the Predatorial Nature is one that vampires hide within themselves. While this nature is suppressed, the vampire appears as a normal corpse moving about. The effects of Delirium cause the vampire to appear as a living mortal to onlookers, however, when the vampire is damaged or when certain factors arise, the vampire risks their Predatorial Nature coming out.

Invoking their NatureEdit

Vampires may invoke their Predatorial Nature at any time. When this happens, their eyes flood red with blood (some, like the Bucoli have their eyes change to black), their fangs extend, the "mask" that Delirium provides leaves revealing their true self and their nails become supernaturally sharpened like small razors on their hands. Example: A mortal who chooses to attack the vampire sees a mortal like any other, however, upon firing at them enough, the vampire invokes his Predatorial Nature. When this happens, the mortal sees the vampire go from being a living, breathing mortal to a corpse standing in front of him. He can feel the vampire's Empathy creeping around him and he notices supernatural qualities. If the vampire is of a sufficiant level, plants die, grass wilts and the world becomes depressing and cold all of the sudden. Watching the vampire, the mortal notices his eyes change from white to red, fangs extend and nails sharpen. This is the real horror the mortal has just met.