Android : Draw tail for ball in a pong game Java LibGDX

I got a working pong game in LibGDX but I'm now trying to add a tail to my ball so if it moves you can see a line behind it just like the game Snake.

I'm drawing simple circles now at the x/y coordinates I get but for some reason this gets messed up I'm not getting any errors.

This is how my game looks like right now:

Here is where I add the x/y coordinates to the tail classes wich I created it works fine but for some reason this gets messed up on my screen.

public void tail(){
    i++;
    if(i >= tail.length)i=1;

    tail[i-1] = new Tail(ball.getX(),ball.getY());
    tail[i] = new Tail(tail[i-1].x,tail[i-1].x);
}

I created the objects like this:

for(int i = 0; i < tail.length; i++){
    tail[i] = new Tail(0,0);
}

And my Tail class looks like this:

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Color;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer;
import com.badlogic.gdx.graphics.glutils.ShapeRenderer.ShapeType;

public class Tail {

    public float x;
    public float y;

    ShapeRenderer shapeRenderer;
    SpriteBatch batch;

    public boolean active = false;

    public Tail(float x, float y){
        shapeRenderer = new ShapeRenderer();
        batch = new SpriteBatch();

        this.x = x;
        this.y = y;

          batch.begin();
          shapeRenderer.begin(ShapeType.Filled);
          shapeRenderer.circle(x, y, 16);
          shapeRenderer.setColor(Color.BLACK);
          shapeRenderer.end();
          batch.end();  

        Gdx.app.log("TailX"+x, "TailY"+y);
    }

}

Why is this not working and is the tail class drawing the circles like the image above? And whats the best way to solve this problem so I get a following tail?!