Yeah. It's a cave spider dressed in a diamond block.
Note: Minify the command to avoid issues :)
Unlucky Potion (NO LUCKY BLOCK NEEDED =])
Dr Trayaurus is in your world!!!!!!!!!!!!
LUCKY WORLD!!!!!
Lucky Potion (NO LUCKY BLOCK NEEDED =])
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)