Scratchmen Apoo serves as a supporting antagonist, originating from the Longarm Tribe. His distinctive physiology features elongated arms with dual elbow joints, enabling a unique combat style centered on musical abilities granted by the Oto Oto no Mi Devil Fruit. This power allows him to transform body parts into instruments, generating sound-based attacks. Targets struck by these sounds suffer slicing damage, concussive blasts, or explosions; covering the ears nullifies the effects. Commanding the On Air Pirates and known as the "Roar of the Sea," Apoo first appeared among the eleven Supernovas at Sabaody Archipelago with a 198,000,000 berry bounty, later rising to 350,000,000 berries. His demeanor blends musical enthusiasm with opportunism; he performs DJ-like movements during combat and celebrations while demonstrating calculated treachery. He exemplified this by forming a fabricated alliance with Eustass Kid and Basil Hawkins, only to betray them to facilitate their forced recruitment into Kaido's Beasts Pirates. During the Paramount War saga, he observed the Battle of Marineford, questioning Trafalgar Law's rescue of Monkey D. Luffy. Following the timeskip, Apoo covertly aligned with Kaido as an informant within the Beasts Pirates hierarchy. His role involved reporting operational disruptions like the loss of contact with Jack during the Zou Arc and participating as a DJ in the Fire Festival celebrations in Wano Country. In the non-canon film "One Piece: Stampede," Apoo participated in the Pirates Festival on Delta Island. He navigated the Knock Up Stream during the Treasure Race competition to locate Gol D. Roger's treasure and joined the pursuit when Buggy the Clown secured the chest. Chaos erupted as Douglas Bullet, a former Roger Pirates crewmate, assaulted the island by throwing a galleon. Apoo joined a coalition of Worst Generation members—Luffy, Kid, Killer, Hawkins, Bege, Bonney, Drake, and Urouge—to confront Bullet directly. His musical attacks proved ineffective against Bullet's resilience. Bullet then deployed his Gasha Gasha no Mi powers to construct a colossal mechanized exoskeleton, overwhelming the Supernovas. After Bullet's defeat, Apoo escaped the Marine encirclement alongside other pirates by leveraging diversionary tactics provided by Sabo and Ann. His design incorporates musical themes: piano-key teeth, orange or black headphones, lightning-patterned hair, and attire adorned with the kanji for "sound" or "music." His laughter manifests as "Apapapapapa." Personality traits include perceptiveness toward hostile intent, enjoyment of provocation preceding retreat, and prioritization of self-preservation over loyalty.