public GameObject mob;
           public float spawn = -2f;
           private float time;
       
           // Update is called once per frame
           void Update()
           {
               time -= Time.deltaTime;
               if (time < 0)
               {
                   Vector2 pos = new Vector2(Random.Range(14.4f, 14.4f), Random.Range(5.5f, -5.5f));
                   Instantiate(mob, pos, Quaternion.identity);
                   time = spawn;
               }
           }