As I didn't draw the junk let's say it's a girl lmao HORSES. U HARD TO DRAW ?????
In European legends one the possible causes of nigthmares was devilish horses (looking like creepy horses but they weren't described with firey manes nor skull heads, I just got inspired and influenced by a book I owned when I was small in which they had a firey mane and in which the anatomy drawing with the skull on fire looked badass as hell) laying on down on people's torso. They are probably the reason we say " nightmare", even if some people protest giving other meanings to the germanic noun "mar"

Nightmares © European folklore
Drawing © me