When I first started playing MC, I made a creative building world and one day I was exploring a desert and I found an awesome cave. When I went inside, I saw two Enderman eyes in the pitch black tunnel ahead. I freaked out(I was twelve at the time) and ran at it, to punch it. Then there was a glitch or something because I think there was a spawner of Endermen, I'll never know tho because I destroyed the entire biome to "Erase" the problem.