Make it rain 100 Spiders

//First you will have to left click the ground while holding a block of any type
//Then you will have to also make sure there is an arrow that is moving that has entered the world but then stopped moving.
//When that happens the spiders will rain
        //Since this is linked to arrows any moving entity Arrow in minecraft that stops moving (aka hits something) will cause
            //100 spiders to rain.
            //Swapping the name EntitySpider with say EntityCreeper, or another Entity will change what happens
                //For some reason in my test build it works but crashes really hard when triggered wonder why? maybe too many
                    //Entities at once? LOL did this with TNT already but for TNT a few more params are required and I didn't show it


package com.example.examplemod;
import java.util.Random;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityCreature;
import net.minecraft.entity.item.EntityTNTPrimed;
import net.minecraft.entity.monster.EntityCreeper;
import net.minecraft.entity.monster.EntitySpider;
import net.minecraft.entity.projectile.EntityArrow;
import net.minecraft.entity.projectile.EntitySpectralArrow;
import net.minecraft.item.Item;
import com.forgeessentials.core.ForgeEssentials;
import net.minecraft.block.Block;
import net.minecraft.block.BlockDirt;
import net.minecraft.world.World;
import com.sun.istack.internal.Nullable;
import net.minecraft.block.state.IBlockState;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.item.ItemStack;
import net.minecraft.util.EnumFacing;
import net.minecraft.util.EnumHand;
import net.minecraft.util.ITickable;
import net.minecraft.util.math.BlockPos;
import net.minecraft.world.World;
import net.minecraftforge.common.MinecraftForge;
import net.minecraftforge.event.AttachCapabilitiesEvent;
import net.minecraftforge.event.entity.EntityJoinWorldEvent;
import net.minecraftforge.event.entity.player.PlayerInteractEvent;
import net.minecraftforge.fml.common.Mod;
import net.minecraftforge.fml.common.Mod.EventHandler;
import net.minecraftforge.fml.common.SidedProxy;
import net.minecraftforge.fml.common.WorldAccessContainer;
import net.minecraftforge.fml.common.event.FMLInitializationEvent;
import net.minecraftforge.fml.common.eventhandler.SubscribeEvent;
import net.minecraftforge.fml.common.gameevent.TickEvent;


import java.util.ArrayList;
import java.util.EnumSet;
import java.util.List;

@Mod(modid = ExampleMod.MODID, version = ExampleMod.VERSION)
public class ExampleMod {
    public static final String MODID = "examplemod";
    public static final String VERSION = "1.0";
    public List<Entity> entitylist = new ArrayList<Entity>();
    public net.minecraft.entity.player.EntityPlayer thisplayer;


    @EventHandler
    public void init(FMLInitializationEvent event) {
        // some example code
        //System.out.println("DIRT BLOCK >> "+Blocks.DIRT.getUnlocalizedName());
        //MinecraftForge.EVENT_BUS.register(this);
        MinecraftForge.EVENT_BUS.register(this);
    }


    @SubscribeEvent
    public void leftClickBlock(PlayerInteractEvent.LeftClickBlock evt) {

        if (evt.getItemStack() != null) {
            EntityTNTPrimed entity;
            net.minecraft.entity.player.EntityPlayer player;
            net.minecraft.world.World world;
            player = evt.getEntityPlayer();
            world = evt.getWorld();

            //entity = new EntityTNTPrimed(world, player.posX, player.posY, player.posZ, player);
            //world.spawnEntityInWorld(entity);

            System.out.println(evt.getItemStack().getDisplayName().toString());
            thisplayer = player;
        }

        if (evt.getItemStack() == null) {
            System.out.println("You don't have anything in hand");

        }

        // When item use denied, the event will keep firing as long as the left click button is held.
        // This is due to how vanilla calls the left click handling methods to let people not lift their button when mining multiple blocks.
        // Note that when item use is denied, the cool down for the item does not occur. This is good!
    }

    @SubscribeEvent
    public void ArrowJoins(EntityJoinWorldEvent evt) {

        if (evt.getEntity() instanceof EntityArrow) {
            System.out.println("An arrow entered the world");
            if (!evt.getEntity().isDead) {
                entitylist.add(evt.getEntity());


            }
        }

    }

    @SubscribeEvent
    public void tickupdate(TickEvent evt) {
        Random myrandomgen = new Random();


        for (Entity ee : entitylist) {
            boolean ground = false;


            if (!ee.isDead) {

                double lastposx = ee.lastTickPosX;
                double lastposy = ee.lastTickPosY;
                double lastposz = ee.lastTickPosZ;

                double currentx = ee.posX;
                double currenty = ee.posY;
                double currentz = ee.posZ;
                double diffx = 0;
                double diffy = 0;
                double diffz = 0;
                boolean differencemajor = false;

                //Get difference in X since last Tick
                if (lastposx > currentx) {
                    diffx = lastposx - currentx;
                }
                if (currentx > lastposx) {
                    diffx = currentx - lastposx;
                }

                //Get difference in Y since last Tick
                if (lastposy > currenty) {
                    diffy = lastposy - currenty;
                }
                if (currenty > lastposy) {
                    diffy = currenty - lastposy;
                }
                //Get difference in Z since last Tick
                if (lastposz > currentz) {
                    diffz = lastposz - currentz;
                }
                if (currentz > lastposz) {
                    diffz = currentz - lastposz;
                }

                if (diffx < 1) {
                    if (diffy < 1) {
                        if (diffz < 1) {
                            differencemajor = true;
                        }
                    }

                }


                if (thisplayer != null) {
                    if (thisplayer.getEntityWorld().isRemote == false) {
                        if (differencemajor == true) {
                            EntitySpider tntentity;
                            net.minecraft.entity.Entity thisarrow;
                            net.minecraft.world.World world;
                            world = ee.getEntityWorld();
                            thisarrow = ee;

                            tntentity = new EntitySpider(thisplayer.getEntityWorld());
                            tntentity.setLocationAndAngles(ee.posX, ee.posY, ee.posZ, 0, 0);
                            world.spawnEntityInWorld(tntentity);

                            for (int a=1;a<300;a++){
                                int posx = myrandomgen.nextInt(200);
                                int posy = myrandomgen.nextInt(30);
                                int posz = myrandomgen.nextInt(200);

                                double newx = (double)posx + ee.posX;
                                double newy = (double)posy + ee.posY;
                                double newz = (double)posz + ee.posZ;
                                tntentity = new EntitySpider(thisplayer.getEntityWorld());
                                tntentity.setLocationAndAngles(newx, newy, newz, 0, 0);
                                world.spawnEntityInWorld(tntentity);





                            }



                            ee.setDead();
                        }
                    }
                }


            }
        }
    }
}