Cannot get the position of this script GameObject

I got a problem, when i’m referencing the gameObject :

Wolf is a class where pos is a Public vector3

Here the code:

public class Hunter : MonoBehaviour {

    Wolf wolf;
    SpawnSheep meat;
    public GameObject hunter;
	// Use this for initialization
	void Start () {
        meat = FindObjectOfType<SpawnSheep>();
        wolf.pos = this.transform.position;
	// Update is called once per frame
	void Update () {
        wolf.pos = this.transform.position;
        for (int x = 0; x < meat.sheeps.Length; x++)
            Debug.DrawLine(wolf.pos, meat.sheeps[x].pos,;

If this is all of the script then wolf is never assigned. Make it public and drag and drop in the inspector or find it the same way you do for the meat variable.

You have defined what a Wolf is, but you never assign an instance of a Wolf to your variable “wolf”.

You need to create a Wolf in your scene somehow, and make the “wolf” variable point to it.