The OP Boss for 1.9+
Note: Minify the command to avoid issues :)
Magic Book By FlashBatMan
RocketJump | One CommandBlock
Coca-Cola by FlashBatMan
Bedrock Sword By FlashBatMan
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)