JPopupMenu drawing over major part of JDesktopPane

Question

I have an issue with JPopupMenu, as the title tries to explain, it's drawing a white box over a major part of JDesktopPanel

This is the code that's responsible for creating the menu:

private void make_creature_creation(){
        JPopupMenu CreateCreatureMenu = new JPopupMenu("Add Creature");
            gameZone.addMouseListener(new MouseAdapter(){
                @Override
                public void mouseClicked(MouseEvent e){
                    if(e.getButton() == MouseEvent.BUTTON3){
                    CreateCreatureMenu.show(thisWorld,e.getX(), e.getY());
                    mouseX = e.getX();
                    mouseY = e.getY();
                    }
                }}
            );
        for (String s : CC.getknownCreatures()) {
            JMenuItem item = new JMenuItem(s);
            item.addActionListener(new CustomActionListiner(s, this));
            CreateCreatureMenu.add(item);
        }

        this.add(CreateCreatureMenu);
    }

If the issue lies in how I draw the image on gameZone, here is code that's responsible for that

public void draw(){
        Graphics g = gameZone.getGraphics();
        g.clearRect(0, 0, gameZone.getWidth(), gameZone.getHeight());
        g.setColor(new Color(255,255,255));
        g.fillRect(0, 0, gameZone.getWidth(), gameZone.getHeight());
        g.setColor(new Color(0,0,0));
        g.drawRect(0, 0, gameZone.getWidth(), gameZone.getHeight()-1);
        style.draw_grid(getColumnCount(), getRowCount(), gameZone);
        for(Creature c : creatures){
            c.draw();
        }
    }