Yeah. It's a cave spider dressed in a diamond block.
Note: Minify the command to avoid issues :)
Green Leather Boots
LUCKY WORLD!!!!!
SICKNESS POTION (4 TROLLING)
Lucky Potion (NO LUCKY BLOCK NEEDED =])
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)