public override bool PreAI()
        {
            if (npc.ai[3] > 0)
                npc.realLife = (int)npc.ai[3];
            if (npc.target < 0 || npc.target == byte.MaxValue || Main.player[npc.target].dead)
                npc.TargetClosest(true);
            if (Main.player[npc.target].dead && npc.timeLeft > 300)
                npc.timeLeft = 300;

            if (Main.netMode != 1)
            {
                if (!Main.npc[(int)npc.ai[1]].active)
                {
                    npc.life = 0;
                    npc.HitEffect(0, 10.0);
                    npc.active = false;
                    NetMessage.SendData(28, -1, -1, "", npc.whoAmI, -1f, 0.0f, 0.0f, 0, 0, 0);
                }
            }

            if (npc.ai[1] < (double)Main.npc.Length)
            {
                // We're getting the center of this NPC.
                Vector2 npcCenter = new Vector2(npc.position.X + (float)npc.width * 0.5f, npc.position.Y + (float)npc.height * 0.5f);
                // Then using that center, we calculate the direction towards the 'parent NPC' of this NPC.
                float dirX = Main.npc[(int)npc.ai[1]].position.X + (float)(Main.npc[(int)npc.ai[1]].width / 2) - npcCenter.X;
                float dirY = Main.npc[(int)npc.ai[1]].position.Y + (float)(Main.npc[(int)npc.ai[1]].height / 2) - npcCenter.Y;
                // We then use Atan2 to get a correct rotation towards that parent NPC.
                npc.rotation = (float)Math.Atan2(dirY, dirX) + 1.57f;
                // We also get the length of the direction vector.
                float length = (float)Math.Sqrt(dirX * dirX + dirY * dirY);
                // We calculate a new, correct distance.
                float dist = (length - (float)npc.width) / length;
                float posX = dirX * dist;
                float posY = dirY * dist;

                // Reset the velocity of this NPC, because we don't want it to move on its own
                npc.velocity = Vector2.Zero;
                // And set this NPCs position accordingly to that of this NPCs parent NPC.
                npc.position.X = npc.position.X + posX;
                npc.position.Y = npc.position.Y + posY;
            }
            return false;
        }

        public override void AI()
        {
            npc.ai[0]++;
            Player P = Main.player[npc.target];
            if (npc.target < 0 || npc.target == 255 || Main.player[npc.target].dead || !Main.player[npc.target].active)
            {
                npc.TargetClosest(true);
            }
            npc.netUpdate = true;

            npc.ai[1]++;
            if (npc.ai[1] >= Main.rand.Next(800, 1200)) //800 is projectile fire rate
                {
                Main.NewText("DEBUG");
                float Speed = 10f; //projectile speed
                Vector2 vector8 = new Vector2(npc.position.X + (npc.width / 2), npc.position.Y + (npc.height / 2));
                int damage = 100; //projectile damage
                int type = mod.ProjectileType("SuperVileSpit"); //put your projectile name here
                Main.PlaySound(SoundID.NPCHit8);
                float rotation = (float)Math.Atan2(npc.Center.Y - (P.position.Y + (P.height * 0.5f)), npc.Center.X - (P.position.X + (P.width * 0.5f)));
                int num54 = Projectile.NewProjectile(npc.Center.X, npc.Center.Y, (float)((Math.Cos(rotation) * Speed) * -1), (float)((Math.Sin(rotation) * Speed) * -1), type, damage, 0f, 0);
                npc.ai[1] = 0;
            }
        }