Congratulations, you have a lidérc.
Call the Winchesters.
The lidérc is one of the most commonly known creatures of Hungarian folk belief. It can actually mean quite a few things:
1. Will-o'-the-Wisps (we call them lidérc lights)
2. Handsome men or women that seduce mortals and then make them sick or dead - sometimes by drinking their blood while they are asleep (lidérc lovers)
3. A chicken from the egg of a black hen, hatched under the armpit of a man (who has to sit still for 6 weeks) - it can bring wealth for its master, but it has to be kept constantly fed and occupied, otherwise it feeds on its owner. (lidérc chicken)
4. A creature that sits on your chest, sometimes drinks your blood, and makes you ill.
Four wonderful options, obviously.
A lidérc sitting on the chest of a sleeping person (and sometimes drinking their blood, or sucking on their nipples until they swell up) (you're welcome, have fun sleeping in a bra) causes a lidércnyomás - literally, lidérc pressure. Not to mention other kinds of pressure, like having to deal with swollen nipples. Brrr.
Lidércnyomás or lidérc dream (lidérces álom) also happens to be our term for nightmares.
The good news: There are ways to get rid of a lidérc.
1. If you are one of those
2. First aid: If a person has a lidérc on their chest, you might try to swat it into a jar with slow hand movements from head to toe. Here is one more thing you can use mason jars for, Pinterest.
3. You can keep them from coming into the house in a couple of ways - mostly with incense or birch twigs, or by magical binding.
4. HOW ABOUT YOU DON'T MAKE ONE.
Be safe, people. Friends don't let friends make a devil chicken under their armpits.
Add a black hen to your Halloween decorations.