Mesh from Code

HappyCube.cs

using UnityEngine;

public class HappyCube : MonoBehaviour {

    MeshFilter mFilter;
    Mesh Mesh;

    public float UpDownFactor = 0.1f;
    public float UpDownSpeed = 6f;
    public float LeftFactor = 0.3f;
    public float LeftSpeed = 3f;
    public float LeftOffset = 2.3f;
    public float StrechFactor = -0.1f;
    public float StrechSpeed = 6f;

    // Use this for initialization
    void Start () {

        Mesh = new Mesh();
        Mesh.name = "Dancing Cube";

        var trigangles = new int[]
        {
            //top/bottom
            0,2,1,
            0,3,2,
            4,5,6,
            4,6,7,

            //left/right
            9,8,11,
            8,10,11,
            12,13,15,
            14,12,15,

            //front/back
            16,17,19,
            18,16,19,
            20,21,23,
            22,20,23
        };

        Mesh.vertices = GenerateVerticies();
        Mesh.triangles = trigangles;
        Mesh.RecalculateBounds();
        Mesh.RecalculateNormals();

        var mFilter = gameObject.AddComponent<MeshFilter>();
        mFilter.mesh = Mesh;
    }

    protected Vector3[] GenerateVerticies(float up = 0f, float left = 0f, float strech = 0f, float forward = 0f)
    {

        return new Vector3[]
        {
            //top
            new Vector3(-1,0,1),
            new Vector3(1,0,1),
            new Vector3(1,0,-1),
            new Vector3(-1,0,-1),

            //bottom
            new Vector3(-1 - strech + left,2 + up,1 + strech + forward),
            new Vector3(1 + strech + left,2 + up,1 + strech + forward),
            new Vector3(1 + strech + left,2 + up,-1 - strech + forward),
            new Vector3(-1 - strech + left,2 + up,-1 - strech + forward),

            //left
            new Vector3(-1,0,1),
            new Vector3(-1,0,-1),
            new Vector3(-1 - strech + left,2 + up,1 + strech + forward),
            new Vector3(-1 - strech + left,2 + up,-1 - strech + forward),

            //right
            new Vector3(1,0,1),
            new Vector3(1,0,-1),
            new Vector3(1 + strech + left,2 + up,1 + strech + forward),
            new Vector3(1 + strech + left,2 + up,-1 - strech + forward),

            
            //front
            new Vector3(1,0,-1),
            new Vector3(-1,0,-1),
            new Vector3(1 + strech + left,2 + up,-1 - strech + forward),
            new Vector3(-1 - strech + left,2 + up,-1 - strech + forward),

            //back
            new Vector3(-1,0,1),
            new Vector3(1,0,1),
            new Vector3(-1 - strech + left,2 + up,1 + strech + forward),
            new Vector3(1 + strech + left,2 + up,1 + strech + forward)
        };
    }
	
	// Update is called once per frame
	void Update () {

        //Walking
        var input = new Vector3(Input.GetAxis("Horizontal"), 0f, Input.GetAxis("Vertical"));
        var inputMagnitude = Mathf.Clamp(input.magnitude, 0, 1);

        transform.position += Time.deltaTime * input * 20f;

        if (inputMagnitude > 0)
            if (Vector3.Angle(input.normalized, Vector3.back) > 1)
                transform.rotation = Quaternion.FromToRotation(Vector3.forward, input.normalized);
            else
                transform.rotation = Quaternion.AngleAxis(180, Vector3.up);

        //Animation
        Mesh.vertices = GenerateVerticies(Mathf.Sin(Time.realtimeSinceStartup * UpDownSpeed) * UpDownFactor,
                                          Mathf.Sin((Time.realtimeSinceStartup + LeftOffset) * LeftSpeed) * LeftFactor,
                                          Mathf.Sin(Time.realtimeSinceStartup * StrechSpeed) * StrechFactor,
                                          inputMagnitude);

    }
}