Players stand in a circle and throw an imaginary ball to each other.
Each throw is accompanied by a sound made by the thrower. The catcher repeats the same sound when receiving the ball. Then the catcher invents a new sound and throws the ball to someone else.
The sounds can be anything — animal noises, machine sounds, vocal effects. The key is to commit fully to each sound and to match the physical weight and size of the throw to the sound.