Adelle Bascùd

Anaguma/Adelle Bascùd is a character that appears in the fourth movie. She was an assistant to a the boiler man (whom she called Grandpa) onboard Gasparde's ship, at first thought to be a boy due to her appearance. However once he was stricken sick, she desperately begged Gasparde to help him. Gasparde made a deal with her that if she could kill a pirate, she would be considered his crewmate and he would help her grandpa. She quickly left the ship to do just that and stowed away on the Going Merry thinking it was the weakest ship, though quickly finds out otherwise when she tries to kill Zoro and travels along with the Straw Hat crew during the Dead End Race. She then asks the Straw Hats to help rescue her grandpa to which they agree. Once they reach Gasparde's ship, her grandpa sends Anaguma with the Straw Hats so he could overload the boiler and blow up Gasparde's ship. When Anaguma cries for the crew to turn back, Zoro knocks her out revealing her gender to the crew when her cap falls off. After Gasparde is defeated, its revealed through her "Grandpa" to Shuraiya Bascùd that he rescued a little girl eight years ago from a river who could only remember her name: Adelle Bascùd, who happens to be Shuraiya's sister whom he thought was dead. Despite some awkwardness at first, she comes to accept Shuraiya who promises to start a new life for the both of them.

Trivia

 * It seems that Tony Tony Chopper knew her gender the entire time, which makes sense since he's a doctor.
 * Anaguma, her nickname, means badger.