A Strange Cave

Me, GamingDefense was playing on the seed WcaveZx and spawned inside a cave. There were iron bars blocking the the entrance so I was basically trapped in there. I turned around seeing a black figure disappear at the corner of my eye.

I walked further down the cave and saw a little hallway carved into the cave, down the hallway was this strange white humanoid that was sitting down so I ignored it. I then walked further in to find a staircase that was not too long, Since I was in creative i didnt bother walking down so i jumped but i took damage.

I walked down another long hallway noticing i dropped into a stronghold and then entered the end portal room. There was no spawner or end portal so i kept walking down the hallway that went through the room. I then entered a room that had alot of caged mobs. I then saw the head of herobrine and entity 303 on a noose next to the black figure i saw earlier. Then i started blinking in game, one time i blinked and i found myself struggling to get off of a noose.

i blinked again and i was in another room. This room had a bunch of dead mobs and players, I saw the same humanoid as before and it looked at me, What i saw of it was a skeleton-like head with white eyes and a 4 foot long opening jaw. after about 1 second after he looked at me i was killed and back in the menu.