How do i check which object was instantiated last?

I need to know how to find out the newest instantiated object. In the code below i need to know so in the HatEnable i only activate the object for the last object instantiated and not all of the objects on the server.

 using UnityEngine;
 using System.Collections.Generic;
 
 public class NetworkManager : MonoBehaviour {
 
     public GameObject standbyCamera;
     SpawnSpot[] spawnSpots;
 
     bool connecting = false;
 
     public float respawnTimer = 0;
 
     private int Hat = 0;
     public GameObject HatCos;
 
     void Start () {
         spawnSpots = GameObject.FindObjectsOfType<SpawnSpot> ();
         PhotonNetwork.player.name = PlayerPrefs.GetString ("Username", "Enter Name");
         Hat = PlayerPrefs.GetInt ("Hat");
     }
 
     void OnDestroy(){
         PlayerPrefs.SetString ("Username", PhotonNetwork.player.name);
     }
 
     void Connect() {
             PhotonNetwork.ConnectUsingSettings ("MultiFPS v001");
 
     }
 
     void OnGUI( ) {
         GUILayout.Label(PhotonNetwork.connectionStateDetailed.ToString() );
 
         if (GUI.Button (new Rect (200, 0, 300, 30), "Respawn or press p DO NOT WHEN ALIVE")) {
             SpawnMyPlayer ();
         }
 
         if (PhotonNetwork.connected == false && connecting == false) {
             GUILayout.BeginArea (new Rect(0,0, Screen.width, Screen.height));
             GUILayout.BeginHorizontal ();
             GUILayout.FlexibleSpace ();
             GUILayout.BeginVertical ();
             GUILayout.FlexibleSpace ();
 
             GUILayout.BeginHorizontal ();
             GUILayout.Label ("Username: ");
             PhotonNetwork.player.name = GUILayout.TextField (PhotonNetwork.player.name);
             GUILayout.EndHorizontal ();
         
 
         
             if (GUILayout.Button ("Single Player")) {
                 connecting = true;
                 PhotonNetwork.offlineMode = true;
                 OnJoinedLobby ();
             }
 
             if (GUILayout.Button ("Multi Player")) {
                 connecting = true;
                 Connect ();
             }
             GUILayout.FlexibleSpace ();
             GUILayout.EndVertical ();
             GUILayout.FlexibleSpace ();
             GUILayout.EndHorizontal ();
             GUILayout.EndArea ();
         }
     }
 
     void OnJoinedLobby() {
         Debug.Log ("OnJoinedLobby");
         PhotonNetwork.JoinRandomRoom ();
     }
 
     void OnPhotonRandomJoinFailed(){
         Debug.Log ("OnPhotonRandomJoinFailed");
         PhotonNetwork.CreateRoom (null);
     }
 
     void OnJoinedRoom(){
         Debug.Log ("OnJoinedRoom");
         connecting = false;
         SpawnMyPlayer ();
     }
 
     void SpawnMyPlayer(){
         if (spawnSpots == null) {
             Debug.LogError ("WTF?");
             return;
         }
         SpawnSpot mySpawnSpot = spawnSpots [Random. Range(0, spawnSpots.Length)];
         GameObject myPlayerGO = (GameObject)PhotonNetwork.Instantiate ("PlayerController", mySpawnSpot.transform.position, mySpawnSpot.transform.rotation, 0);
         GameObject HatCos = myPlayerGO.transform.FindChild ("Hat").gameObject;
         standbyCamera.SetActive(false);
         ((MonoBehaviour)myPlayerGO.GetComponent("FirstPersonController")).enabled = true;
         ((MonoBehaviour)myPlayerGO.GetComponent("PlayerShooting")).enabled = true;
         myPlayerGO.transform.FindChild ("FirstPersonCharacter").gameObject.SetActive (true);
         myPlayerGO.transform.FindChild ("Gun").gameObject.SetActive (false);
         myPlayerGO.transform.FindChild ("Face").gameObject.SetActive (false);
         myPlayerGO.transform.FindChild ("Minimap tag Red").gameObject.SetActive (true);
         myPlayerGO.transform.FindChild ("Hat").gameObject.SetActive (false);
         if (Hat == 0){
             Debug.Log ("Hat = false");
             return;
         }else{
             HatEnable (myPlayerGO);
         }
     }
 
     [PunRPC]
     void HatEnable(GameObject myPlayerGO){
         GameObject HatCos = myPlayerGO.transform.FindChild ("Hat").gameObject;
         HatCos.SetActive (true);
         HatDisable (myPlayerGO);
     }
     void HatDisable(GameObject myPlayerGO){
         GameObject HatCos = myPlayerGO.transform.FindChild ("Hat").gameObject;
         HatCos.SetActive (false);
     }
 
     void Update (){
         if (Input.GetKeyDown ("p")) {
             SpawnMyPlayer ();
 
         }
     }
 }