this happened to me 3 times. in korean direct translation is called "sicssor lock"
its when i wake up, but i cant move my body, but ii can move my eyes.
the first time i experienced. i woke up, and i could see the figure of a woman in my periferic view walking away from sight, while listening to a really creepy "puhahahahahahahaha"
it was really scary, and it wouldnt go away for like 10 mins which felt like forever.
the second time.
i woke up and again i couldn't move but my eye balls, and on top of me there was this black blanket floating. it seemed like a flag waving. it was really creepy too.
and then it happened a couples of time after but i didn't see anything, but it was still creepy. the best way to terminate this was to force myself to fall back asleep.