Tony Tony Chopper is a reindeer who consumed the Human-Human Fruit (Hito Hito no Mi), gaining human intelligence, speech, and transformation abilities. Originally from Drum Island, his herd ostracized him for his blue nose and unnatural powers. The quack doctor Hiriluk adopted him, instilling a passion for medicine. Following Hiriluk's death, Chopper apprenticed under Dr. Kureha, refining his medical expertise. His background of rejection and found family led him to join the Straw Hat Pirates as their doctor, pursuing his dream to cure any disease. Chopper typically appears in a small hybrid human-reindeer form, wearing a large pink hat bearing a medical cross, a legacy from Hiriluk. His Devil Fruit grants three standard transformations: Brain Point (small hybrid), Heavy Point (humanoid), and Walk Point (reindeer). He developed the Rumble Ball, enabling four additional combat forms: Jumping Point, Guard Point, Arm Point, and Horn Point, each enhancing specific physical attributes like leg agility, defensive fur, arm strength, or antler size. Post-timeskip training expanded his control, allowing access to forms like Kung Fu Point without Rumble Balls and temporary mastery of the life-draining Monster Point. In *The Giant Mechanical Soldier of Karakuri Castle*, Chopper accompanies the Straw Hats to Mecha Island after they rescue an old lady promising a golden crown treasure. His ability to understand animal language proves critical when he perceives a voice calling out during exploration. This voice belongs to the giant turtle forming the island itself. Chopper's communication reveals its purpose: awakening every millennium to lay eggs. His medical knowledge and empathy drive him to aid the creature, separating from the crew during the climax to ensure its safety. During the island adventure, Chopper participates in deciphering the "Yurari Uta" riddle for the Golden Crown. He witnesses Luffy misinterpret the lyric "two moons" as celestial bodies, later corrected by Robin to mean "strike," leading to the discovery of a cave entrance. Though initially attending a deceptive party hosted by the island's leader Ratchet, Chopper's focus shifts to the turtle's distress as Ratchet attempts world domination using a mechanical castle controlling the creature. In the resolution, Chopper learns the Golden Crown refers to the turtle's eggshells, fulfilling the treasure legend. Beyond this film, Chopper's role includes developing advanced medical solutions, such as antidotes for lethal viruses. His ability to communicate with animals remains a recurring skill, facilitating translations between species. A spin-off project, *Chopper's*, depicts him living slice-of-life scenarios in the real world, exploring daily activities like cooking or photography, distinct from his cinematic adventures.