A SUPER SKELTON
Note: Minify the command to avoid issues :)
Wither with an Ocelot?
A Nether Dragon! :0
Minecraft: New Minecraft Mode: IMPOSSIBLE
Mutant Skeleton OMG
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)