Animation Scripting Help #C

I keep getting this error: NullReferenceException: Object reference not set to an instance of an object EnemyAnimation.Start () (at Assets/The Game/Scripts/EnemyAnimation.cs:24)

I am really new to this and I would really appreciate some help!

 using UnityEngine;
 using System.Collections;
 
 public class EnemyAnimation : MonoBehaviour
 {
         Animation _animation;
         // Use this for initialization
         void Start ()
         {
                 _animation = GetComponentInChildren<Animation> ();
                 string animationToPlay = "";
                 switch (Random.Range (0, 3)) {
                 default:
                 case 0:
                         animationToPlay = "Move1";
                         break;
                 case 1:
                         animationToPlay = "Move2";
                         break;
                 case 2:
                         animationToPlay = "Move3";
                         break;
                 }
         _animation [animationToPlay].wrapMode = WrapMode.Loop;
         _animation.Play (animationToPlay);
         _animation[animationToPlay].normalizedTime = Random.value;
         }
     
         // Update is called once per frame
         void Update ()
         {
 
         }
 }