Tony Tony Chopper/Abilities and Powers

Abilities and Powers
Though it is rare for doctors to fulfill roles other than medical practices for the benefit of those around them, but as the Straw Hats' doctor, Chopper's responsibilities are not limited to medicine alone.

He occasionally performed tasks like steering the ship as their unofficial helmsman while on the Going Merry. But during battles, he can fulfill the role of a physical fighter. However, due in part to his lack of battle experience or formal training (as well as his Rumble Ball's time limited effect) Chopper was originally considered part of the "Weakling Trio" along with Nami and Usopp. This lay largely in his lack of battle intuition and naivety at the time, though it is implied that he has gotten much more capable after his two years of training.

Medical Expertise
Chopper being the doctor of the crew, has a vast knowledge of medicine and medical drugs as well as the preparations of remedies and ointments from regular fruits, roots, and vegetables that can be found on most islands.

Most of this was from the things he learned during his apprenticeship under Dr. Hiluluk and Dr. Kureha, with the latter teaching him most of the medicinal procedures that he has mastered. It is currently unknown how much his medical abilities have improved after the timeskip.

Is should be noted that while he was under the apprenticeship of Dr. Kureha, Chopper was able to learn of the highly addictive drug NHC10, and its dangerous side effects.

Devil Fruit
Chopper has eaten the Zoan-class Devil Fruit called the Hito Hito no Mi, which allows him to transform into a human and human-reindeer hybrid. However, the fruit has granted Chopper more than just the ability to transform; it also gave him human intelligence, allowing him to speak and think like a human. This is what allowed Chopper to become a doctor and learn about medicine, which is impossible for a normal reindeer. Chopper usually remains in his human-reindeer hybrid form, which is a tanuki-like chibi-creature. While in combat, he tries to transform into what best suits the situation.

Rumble Ball
In addition to his three forms granted by his Devil Fruit, Chopper has invented a yellow jaw-breaker like drug called the Rumble Ball through some research. This drug distorts the wavelengths of the Devil Fruit's transformation, allowing him to access one additional transformation (four before the timeskip) for three minutes.

However, due to the risk of this alteration, the Rumble Ball's consumption must be closely monitored, and for this reason Chopper cannot consume more than one every six hours. If he takes a second one, his transformations would become out of control. And if a third one is taken, Chopper transforms into a massive, berserk monstrosity (as witnessed at Enies Lobby and Sabaody Archipelago) with equally monstrous strength that requires lethal amounts of energy to keep active, making Chopper a danger to both himself as well as others.

After the timeskip Chopper reveals that he only needs to take a Rumble Ball for one transformation now, his "Monster Point", which Chopper now has full control over. However, how he did this is currently unknown.

Other Combative Capabilities
In addition to the transformational advantages that Chopper's many forms afford him in battle, he has also been known to employ wrestling-type moves (i.e.pinning down an opponent, or smashing them to the ground by means of supplex) from time to time. His extensive knowledge of the bipedal anatomy has also proved useful when the Straw Hats were trying to bring down Oars, during which time, Chopper formulated several theories on where it was best to target the colossal adversary, and finding the giant's weak spot. And while naive, he can also be quite a capable strategist, as seen in his fights against the Mr. 4 pair and Gedatsu.

Chopper, who was originally an animal, is also capable of communicating with and understanding other animals, which has come in handy during certain points in the story. He also has a sensitive nose that can be used for tracking others (except during rainy weather). But because his nose is so sensitive, strong aromas such as perfumes can irritate his sense of smell.

Chopper also seems to have a technique called Tranquilizer (sometimes translated as Sedative, as is the case with the English manga), which involves Chopper injecting a substance, possibly an anesthetic, into the opponents body making them faint. This was first used on Luffy when he had a hallucination of a tsunami about to hit them while walking to Yuba in the Alabasta Desert.

After the two-year timeskip, he is seen being able to perform formidable martial art maneuvers with his new form called, "Kung Fu Point", and is now able to produce a new "Horn Point" with larger "Stag Beetle" like antlers which are useful for digging in the ground at high speeds. He also tells of how he only needs the Rumble Ball for one of his forms which was revealed to be his unnamed, "Monster" form.