What things have you seen during sleep paralysis?

What is this “monster” that leaves you tangled in your body, unable to move or shout? It depends on who you ask. For some, it is a faceless, shapeless presence trying to choke them.
Others characterize it as a creepy old hag with claws, and some see an alien and experience what they believe is alien abduction. And for others, the monster looks like a dead relative.
All cultures have different explanations for sleep paralysis. Canadian Inuit attribute it to the spells of shamans. Japanese folklore tells of a vengeful spirit that suffocates its enemies in their sleep.
In Brazilian folklore, the monster has a name — Pisadeira, which in Portuguese means “she who steps.” She is a crone with long fingernails who creeps on rooftops in the night, then walks on the chest of anyone sleeping belly up on a full stomach. Aside from these tales, sleep paralysis is a real thing. The sensation of ~seeing~ something monster-like while experiencing sleep paralysis is also natural. It is called a hypnagogic or hypnopompic hallucination.
As for the monster itself, it’s not real. We promise. Yet, there might be a speck of truth to the belly-up part of the Brazilian myth. It turns out you are more likely to experience sleep paralysis when sleeping on your back.