I had something like this as a kid. One episode I remember vividly was where I woke up, looked around, and the room was filled with metallic flying saucers eac

I had something like this as a kid. One episode I remember vividly was where I woke up, looked around, and the room was filled with metallic flying saucers each about the size of a large potato, whizzing past my head, clanging as they bumped into each other, and I "knew" they would kill me if they noticed me. It was fascinating but terrifying. It didn't feel at all like how "waking up in a dream" does—I was definitely conscious—I checked, introspectively observing that I could control my thoughts. I hid under the blanket for what must have been at least a few minutes until the whizzing and clanging suddenly stopped, then anxiously checked that the saucers were gone, and fell asleep again. Probably unrelatedly, I would also occasionally unexplainedly faint, so I was tested for epilepsy and sleep issues because of that. Both came up clean. The sleep terrors thankfully stopped partway through primary school. I still have the unexplained fainting, but that's a story for another comment.