I unno, there was one that still sticks into my head this day, but I'm still wondering if I can recall the details fully. It must've been lucid, otherwise I wouldn't have felt like I was completely immersed in the dream. It was something almost out of a creepypasta, where I was going into the abandoned mining cavern to go exploring for minerals with a friend of mine. Him and I were going into these seemingly infinite caverns and as we got deeper and deeper, the environment felt colder and much more... empty. Everything was pitch black except for our flashlights, the floors eventually became barren and natural and you couldn't even hear a sound in that place. I decided to go off and explore a tributary on my own for some reason and somehow lost my friend. My flashlight eventually went dead and I only had my nightvision to support me through walking through. I think in the dream I thought my eyes were playing tricks on me, but I could've sworn I saw things moving outside my vision. Suddenly I couldn't cry out for my friend or call for help, I tried running but the black figures seemed to move with me with very natural human movements. After I got a good look at them they seemed to have white masks with just two black circles for eyes. Their bodies were emaciated, long and black like ink. They didn't try to harm me, they just followed me. Some minutes passed and I think I found a shaft that lead upward with a exit above, so I climbed the hell out of there and made it back outside, with the figures just completely disappearing below me. I woke up in a cold sweat that night and I still think about the nightmare from time to time.