Also works with magma cubes -
/summon LavaSlime ~ ~ ~ {Size:20}
Note: Minify the command to avoid issues :)
SUPER ARMOR!!!!!!!!!!!!! #2:Leggings
GIANT SLIME
Iron golem spawner
VERY FAST BOOTS!!!!!!
Pet ENDER DRAGON!!!!!
Wither Storm Boss in ONE COMMAND
HEROBRINE COMMAND
HEROBRINE BOSS BATTLE (See YouTube for details)