Xenodochial Creepers are an extremely rare species found only in deep caves. Their unnatural habit of beign passive towards players makes them stand out. They are 1.7x bigger than a normal creeper and have the attributes of players; they can dig, use tools, and always have a stash of potions. This combination of abilities is not shared by any other mob.
Often when venturing in a cave, there is a small chance that a Xenodochial Creeper will be living in it. After attacked and killed by a mob, instead the screen turns black and sounds are played in the background for a few seconds, then the player will wake up sleeping in a bed. The health and hunger bar will be full and they will be standing in a cave with a Xenodochial Creeper.
Xenodochial Creepers are found in caves. Well, they find you. However, it is extremely rare to be found by one. After supposedly 'dying', all the player's items will still be with them.