You can use an action to play the flute and then throw it on the ground within 10 feet of you. The flute becomes a Clockwork Iron Cobra under your control and acts on its own initiative count. By using a bonus action to play the flute again, you return it to its normal form in a space formerly occupied by the Cobra.

Each time the Cobra is summoned, you must roll a d10 for one of the Clockwork enhancements and a d10 for one of the Clockwork malfunctions (rolling 9 or 10 results in no malfunctions) that will manifest for the duration of the summoning. 

On your turn, you can mentally command the Cobra if it is within 60 feet of you and you aren't incapacitated. You decide what action the Cobra takes and where it moves during its next turn, or you can issue it a general command, such as to attack your enemies or guard a location.

If the Cobra is reduced to 0 hit points, it dies and reverts to its flute form. The flute then shatters and is destroyed. If the Cobra reverts to flute form before losing all its hit points, it regains all of them.

Notes: Bard with the ability to play a Flute