1, plastic balloon: ordinary small plastic balloons are filled with air and then fixed together with thin lines or adhesive tapes, which can form an effect similar to an ocean ball.

2. Foam balls: You can buy foam balls of different sizes in some handicraft shops or online. These balls are light and elastic, somewhat similar to ocean balls.

3. Cloth ball: a small ball made of waste clothes or cloth, although different in texture from ocean balls, can also be used as a substitute.