Enderman

Endermen are frightening monsters; while not from another planet they are from the End, another dimension adjacent to our own. Though not directly hostile, they are apparently extremely territorial and will attack anything that looks them in the face or that attacks them first.

Out of Universe information
Endermen have purple eyes that glow. Though (likely) originating from the End, they can appear in the overworld and can function normally. They have the ability to teleport and have glow effects like a nether portal. They are hurt by water and can be damaged by simply stepping into it. They fight skeletons if they are shot and are attacked by iron and snow golems. Upon death, Endermen will drop ender pearls that can be used to find the End portal (if crafted into an eye of the ender) or to teleport. Endermen do not attack in creative mode unless attacked and do not spawn in peaceful.

Trivia

 * The Endermen were based on the fictional "cryptid" monster, Slenderman, which is best known for appearing in a series of popular memes and as the antagonist of the PC game Slender.
 * A popular fan joke is that they are allergic to water, explaining why they are hurt by it. This info however, has never been stated by mojang and is not cannon

Appearances

 * Minecraft