DOTweenTest.cs

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using DG.Tweening;

public class DOTweenTest : MonoBehaviour
{
    // Unity-chan Animator
    public Animator animator;

    IEnumerator Start ()
    {
        transform.localPosition = new Vector3 (0, 0, -5.8f);
        // 再生開始
        var tw = transform.DOLocalPath (
            new Vector3[]
            { 
                new Vector3 (2.6f, 0, -2f), 
                Vector3.zero 
            }, 
            4f, PathType.CatmullRom)
            .SetLookAt (0.3f, Vector3.forward)
            .SetEase (Ease.Linear);
        animator.SetFloat ("Speed", 1f);

        yield return new WaitForSeconds (3f);
        // Animator, Tween共に巻き戻し
        animator.SetFloat ("Speed", -1f);
        tw.PlayBackwards ();
        yield return new WaitForSeconds (3f);
        // Animator, Tween共に2倍速
        animator.SetFloat ("Speed", 2f);
        tw.PlayForward ();
        tw.timeScale = 2f;

        // Tweenの終了を待機
        yield return tw.WaitForCompletion ();

        // Animator, Tween共にスピードを元に戻す
        animator.SetFloat ("Speed", 1f);
        tw.timeScale = 1f;
        animator.SetTrigger ("Idle");
    }
}