Tony Tony Chopper (トニートニー・チョッパー Tonī Tonī Choppā?) is a doctor and a blue-nosed reindeer. The power of the Zoan-type Human-Human Fruit (ヒトヒトの実 Hito Hito no Mi) provides him with the ability to transform into a reindeer or a reindeer hybrid. A self-developed drug he calls Rumble Ball (ランブル・ボール Ranburu Bōru) enables Chopper to perform even more transformations. When complimented, Chopper acts really sad while either yelling at the animal who complimented him to stop trying to make him happy, or that Chopper is not very happy. His voice actress is Ikue Ōtani. In the 4Kids and Funimation English adaptations, his voice is supplied by Lisa Ortiz and Brina Palencia, respectively.
When creating Chopper, Oda wanted a mascot who is both cute and very weak. An IGN review of the manga praised Chopper’s character as one of the best in the series and said that he was able to be both touching and funny. With Chopper’s back story, Oda wanted to illustrate that one need not be blood-related to be considered family.
source: https://en.m.wikipedia.org/wiki/List_of_One_Piece_characters
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