Wisps, Demons, Monkey Command Block 1.8.8
Only spawn in the nether. They are very rare.
Demons will attack with melee, TNT, arrows, and zombie pigmen.
Demons can anger zombie pigmen.
Spawn commonly in the jungle (mostly night), uncommonly in the forest, extremely rarely anywhere else.
They are mostly aggressive.
They will climb trees to reach the player or to get away from the player.
They can also hide in the trees.
They have a 50% chance to drop leather.
Spawns uncommonly underground, uncommonly in the mega taiga, and extremely rarely anywhere else.
They fly around passively and will not follow the player.
They attack the player with lightning strikes, and poison if you get too close.
They can only be killed by absorbing their power with a Mage’s wand. (Hold a mage’s wand nearby to do this)
How to install:
To add any one-command creation to your world, first give yourself a command block with /give @p command_block.
Next, place it and paste the following command inside it.