MY BEST FRIEND!
Note: Minify the command to avoid issues :)
Skeleton Knight (1.9.1)
More blocks in ONE command
FLYING MOBS!!! (Are flying only if you spawn him in the air) (no gravity)
Creeper Firework
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)