I used MrGarretto's command combiner, so this is not entirely mine.
Note: Minify the command to avoid issues :)
Herobrine's Head
INVINCIBILITY SWORD
Ultron Prime v2 in Minecraft!
Mojang has sent you a package!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)