Easy it's just a Ghast Riding a GIANT
Note: Minify the command to avoid issues :)
Killer Blaze Rod
Diginer's Axe
Troll Potion (Troll ur m8s)
The Creepiest Giant EVER
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)