Bleak and terrifying. Slimy and cold. These are the true scary beasties of the magical realm…

The stuff of nightmares

The first time we meet the Dementors is in Harry Potter and the Prisoner of Azkaban. There is Harry, happily relaxing in his carriage next to a snoozing Lupin when suddenly things go dark and, frankly, terrifying. The creature which opens the door to his cabin is not something you’d like to meet on a dark night. Actually, it isn’t something you’d like to meet on a bright sunny day with one thousand lamps burning at the same time.

There was a hand protruding from the cloak and it was glistening, greyish, slimy-looking and scabbed, like something dead that had decayed in water ...
Harry Potter and the Prisoner of Azkaban

URGH.

We reach a whole new level of grim when it decides to breathe.

And then the thing beneath the hood, whatever it was, drew a long, slow, rattling breath, as though it was trying to suck something more than air from its surroundings.
Harry Potter and the Prisoner of Azkaban

Reliving your worst trauma

Next thing, Harry hears screaming and passes out. At least with a dragon you know what you’re going to get – a cranky creature which shoots flame and tries to kill you. It’s an honest engagement without any creepy jiggery-pokery. Unlike the Dementors, who don’t just float menacingly with slimy body parts and the ability to freeze the air around you, but also force you to relive your bleakest and most heart-breaking moments.

‘Not Harry, not Harry, please not Harry!’
‘Stand aside, you silly girl ... stand aside, now ...’
‘Not Harry, please no, take me, kill me instead –’
Harry Potter and the Prisoner of Azkaban

Dementors don’t care who you are or what you’ve done. They can see through disguises, and tricks won’t dissuade them. As Dumbledore points out: ‘It is not in the nature of a Dementor to understand pleading or excuses.’

They make other creatures look… nice

While spiders, dragons and giants may be big and shudderific (what’s with Grawp and his perpetually runny nose anyway?) the Dementors make them look positively cuddly. It would be far less revolting to keep a pet spider than have a Dementor round for tea. According to Professor Lupin:

‘Dementors are among the foulest creatures that walk this earth. They infest the darkest, filthiest places, they glory in decay and despair, they drain peace, hope and happiness out of the air around them. Even Muggles feel their presence, though they can’t see them. Get too near a Dementor and every good feeling, every happy memory, will be sucked out of you. If it can, the Dementor will feed on you long enough to reduce you to something like itself – soulless and evil. You’ll be left with nothing but the worst experiences of your life.’

Harry Potter and the Prisoner of Azkaban

The Dementors’ Kiss

The Dementors, unlike other scary magical beasties, keep on giving in the terrifying stakes with the Dementors’ Kiss. This is the worst kind of horrible as the Dementor locks its jaws on the mouth of a victim and sucks out their soul.

‘You can exist without your soul, you know, as long as your brain and heart are still working. But you’ll have no sense of self any more, no memory, no ... anything. There’s no chance at all of recovery. You’ll just – exist. As an empty shell. And your soul is gone for ever ... lost.’

Harry Potter and the Prisoner of Azkaban

Then let’s just add in another morsel of monstrousness – Dementors have no eyes. They feel their way towards people by sensing their emotions. Just, no.

Where there should have been eyes, there was only thin, grey, scabbed skin, stretched blankly over empty sockets. But there was a mouth ... a gaping, shapeless hole, sucking the air with the sound of a death-rattle.
Harry Potter and the Prisoner of Azkaban

Oh, and on top of everything else, this is one creature sorely in need of a breathmint…

…he could smell the Dementor’s putrid, death-cold breath filling his own lungs, drowning him…
Harry Potter and the Order of the Phoenix

Dark alliances

Finally, the Dementors win the award for Most Loathsome Creatures Ever™ because Voldemort sees them as his natural allies and he’s right. Any creature that thinks he is the one to watch, is one to, well, watch. A fact that Cornelius Fudge forgot at great cost.

‘The rest of us sleep less soundly in our beds, Cornelius, knowing that you have put Lord Voldemort’s most dangerous supporters in the care of creatures who will join him the instant he asks them!’ said Dumbledore. ‘They will not remain loyal to you, Fudge! Voldemort can offer them much more scope for their powers and their pleasures than you can!’
Harry Potter and the Goblet of Fire