That's the thing, I was playing there in Creative mode like a puffy noob, when I noticed the fact that all the mobs and items had the texture of an emerald on top. You can see that it is a bug due to the fact that they do not drop emeralds, the one from my inventory was there a while ago because there were some ruins. In the videos below you can see the bug in more detail. I hope they fix it soon, because it is quite strange to see mobs with emeralds, and I do not think I can get used to it or other people who have this error. The videos are in order, so you will not have any problem.