A mare (Old English: mære; Danish, Norwegian: mare; Swedish: mara; Polish: mara, zmora; among many others) is a malicious entity in Germanic and Slavic folklore that sits, walks, or “rides” on people’s chests while they sleep, bringing on nightmares.[1]
The mare was believed to ride horses, which left them exhausted and covered in sweat by the morning.
Horse?
(this reply is related to the painting the meme is based on)
https://en.wikipedia.org/wiki/Mare_(folklore)
yes.
The original by fuseli also had a demon sitting on her rather than the dog. Maybe the horse should be photoshop replaced with a bowl of guac