IEnumerator DoInstaKill()
    {
        ZombieSquad.Instance.DeathZombie(this);
        _zombieAI.SetDeath();
        iTween.ScaleTo(gameObject, iTween.Hash("scale", Vector3.zero,
                                               "easetype", iTween.EaseType.easeInBack,
                                               "time", 0.3));
        yield return(new WaitForSeconds(0.3f));

        Destroy(gameObject);
    }