Phantom Creeper

most creepypastas are about a player-like entity. this... thing... is unlike anything I've seen in minecraft. I was in a small cave in the side of a mountain in an acacia biome, mining, when I saw what looked like a creeper on my crosshairs, but it had the spectral effect, so I could see it through the wall (above screenshot). I wondered how it could have that effect, since the spectral effect could only be inflicted by spectral arrows. I decided to go closer, and as I travelled around none of the mobs attacked me, it was like they stopped working. when I got closer I could fully see it, and I don't know how to describe it (below screenshot). it was like a creeper, except it wasn't. it just stood there, and shortly after the game crashed. when I launched the game again, the world was gone. it was a very weird and creepy encounter