I used MrGarretto's command combiner, so this is not entirely mine.
Note: Minify the command to avoid issues :)
Splash Potion of Milk!
Velocity 9 (The Flash)
Batman Chestplate
Mojang has sent you a package!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)