Minecraft Dungeons:Enderman

Endermen are hostile mobs that act as mini-bosses in Minecraft Dungeons that have the ability to teleport away from players.

Spawning
The Enderman will spawn in Default difficulty as a mini-boss in Soggy Swamp, and the Desert Temple. In Adventure difficulty, it would spawn sometimes in the Creeper Woods and the Cacti Canyon, and in Apocalypse, it would spawn sometimes in the Redstone Mines and the Fiery Forge.

Behavior
Endermen teleport away after taking damage, and can damage players heavily.

Endermen can't teleport inside walls. They also can "hide" within teleportation and not appear right away.