slimes

@SuppressWarnings("deprecation")
	@EventHandler(priority = EventPriority.HIGH)
	public void onCreatureSpawn(CreatureSpawnEvent e){
		Entity en = e.getEntity();
		int x = 0;
		for (Entity ent:en.getNearbyEntities(25, 25, 25)){
			if(ent.getType() == en.getType()){
				x++;
			}
		}
		if(x >= 18){
			e.setCancelled(true);
		}
		if (en.getType() != EntityType.SLIME){
			if (e.getSpawnReason() == SpawnReason.NATURAL){
				if(en instanceof LivingEntity){
					Block bl = en.getLocation().getBlock().getRelative(BlockFace.DOWN);
					if (bl.getType() == Material.DIRT && bl.getData() == 2){
						en.remove();
						en.getWorld().spawnEntity(en.getLocation(), EntityType.SLIME);
					}
				}
			}
		}
	}