public static Skeleton skeletronBoss(Location boss) {
   Skeleton skeleton = (Skeleton) boss.getWorld().spawn(boss, Skeleton.class);
   skeleton.setCustomName(ChatColor.RED + "Skeletron");
   skeleton.setCustomNameVisible(true);
   skeleton.setMaxHealth(250.0);
   skeleton.setHealth(250.0);
   skeleton.setRemoveWhenFarAway(false);
   return skeleton;
 }