One Piece is highly acclaimed for its expansive world-building featuring numerous unique races and creatures. From the more common giants to the more original Lunarians, the series' catalog of notable folks only expands as years go by. The franchise is also no stranger to weird and unique abilities majorly because of the Devil Fruits' existence. By combining the various races and diverse Devil Fruit powers, Eiichiro Oda manages to create unique characters like Scratchmen Apoo.
Apoo hails from the Longarm Tribe, a race with an extra upper limb joint, and a member of the Worst Generation. He was the captain of On Air Pirates but was absorbed by Kaido's Beast Pirates post-time skip. He climbed the Beast Pirates' rankings by working as Kaido's informant. He allied with and betrayed Eustass Kid and Basil Hawkins, resulting in the former's capture and the latter's recruitment. While he's proved to be an efficient antagonist, there's little knowledge of how his power work.
Apoo ate the Paramecia Devil Fruit Tone-Tone Fruit, allowing him to turn parts of his body into various musical instruments. He commonly uses his teeth like piano keys and his jaws as cymbals to play certain tunes that can affect his target. While seemingly similar to Brook's soul music, Apoo's power can do more than just hypnotism. He can also cause physical damage as he has shown on multiple occasions.
When Luffy and Zoro first wreaked havoc at Queen's party, Apoo was the first to notice and stop them. He used his music to hit Luffy and cut Zoro without touching them. Luffy wasn't able to dodge the attacks and got knocked out, and Zoro was left with no choice but to snatch his unconscious captain and run. When Luffy regained his consciousness for round two, Kid had already launched himself towards Apoo to settle their score.
Killer explained that Apoo's ability revolves around sound. His attacks are effective within hearing range and are almost instantly executed. However, it also has its limitations and drawbacks. Apoo can only target those who he's looking at, like what he did to Luffy, Zoro, and Kid, making his attacks easier to predict. While it seemed to be overpowered, it has an obvious weakness. The ability is rendered ineffective as long as the sound is not heard. This can be done by leaving the hearing range or by simply covering one's ears.
Even though One Piece has shown Apoo using his power on multiple occasions, he is yet to face a desperate situation that forces him to bring out his entire arsenal. That said, it may be safe to assume that he is still hiding one or two trump cards up his sleeve. Fans can only stay tuned in future chapters of One Piece to know what that may be.
