This mob is a normal neutral shapeshifter. It may spawn anywhere, causing a "leaked" creeper myth. It may shift into any creeper once agrovated or its wraith form causing its name the Creepshifter.
The creepshifter is slightly stronger than the iron golem, with it having 105 <3, and doing 2 damage per hit. The creepshifter has enderman behavior, causing it to teleport behind you after it shifts and dissapears into smoke. Once killed it will drop gunpowder and 1 to 2 emeralds to trade with.
It is impossible to farm such a mob, due to it teleporting behind the player.
This mob is often found hiding under blocks and in strongholds, causing the ender portals to be a bit harder to get to. So be careful when you see that diamond ore next time!