Droctopus.

The Droctopus produces sound if you tap the top of the Droctopus with the ruler, strum the strings, tap the material of the eyes gently and move the ruler along the legs.

This is how you make the sound.

When you tap the top of the Droctopus it creates sound waves which echoes around inside of the toilet paper rolls creating sound. By tapping lighter and harder and in different places the notes will change.

The strings are made of rubber bands which vibrate creating sound waves the thicker rubber bands make lower notes and the thinner rubber bands make high notes. Strumming different strings will make different notes.

Tapping the eyes gently will make sound waves which echoes inside of the toilet paper rolls making sound. The sound can be changed just by tapping softer and harder in different places.

If you move the ruler along the legs quickly makes sound waves which echoes inside of the toilet paper roll. Moving the ruler along the legs at different speeds and along different legs will change the sound.