The Dementors are without doubt the most terrifying creatures in the Harry Potter series. The guards of Azkaban are enough to strike fear into the heart of the darkest wizard and are presented as really the only thing Harry Potter fears. Born out of darkness and decay, the Dementors drain all goodness from the world around them and you must never lock lips with a Dementor - no matter how attracted you might be to it - as its kiss has the power to draw your soul from your body, leaving you a lifeless husk. As with lots of Rowling's creations, the Dementors are drawn from traditional archetypes, in this case, the classic image of the Grim Reaper. The dark, faceless figure in a hood and cloak is something that is ingrained into us to fear and the Dementors embody that perfectly. They are also interesting on a metaphorical level (if that's the kind of thing that floats your boat - hey, look there's another metaphor) as they were intended to act as a personification of depression, i.e. they suck you dry of happiness, they are a threat that cannot always be seen, making them one of the more loaded Potter creations.
