Cannot assign prefab in Inspector?

Hello, I'm following along with the Unity Game Development Essentials book and am up to chapter 6, I've declared a rigidbody prefab in the script that I want to instantiate, but I can't assign this in the inspector (it shows that there are no rigidbody prefabs...?), the only way I can define something is by having it in the scene, which does not work.

The code I am using is

var coconutObject : Rigidbody;

I have no idea what is going on here...

That works fine for me assuming you drag the prefab from the project window into the inspector field. It won't show up on the drop down list, though.

Hi, same problem hereā€¦ I have to variables here in my Code I want to Assign one of the variable of type Rigidbody with a prefab. This Fails. On the second Variable of Type Transform this works Fine. (I try to use both Drag and Drop and the List)

public class ShootBullet : MonoBehaviour {
	public Rigidbody BulletPrefab;
	public Transform CylinderEnd;
	// Use this for initialization
	void Start () {
	// Update is called once per frame
	void Update () {
			//var bullet = Instantiate(

Any Suggestions?