Endermen are purple, glowing humanoids. They seem to possess all kinds of end magic, including telepotation. They can also weaken terrain to pull out small chunks. They are almost twice the size of a normal human.
Endermen can be found in both the overworld and the end. It is unknown where endermen come from, but it is most likely the end due to its huge enderman population. Although there is an enderdragon in each major island in the end, they do not seem to rule, as endermen will immediatly retaliate to any harm the enderdragons due. Looking at someone above the knees is considered a rude gesture and threat, and all endermen will react with violance.