Tony Tony Chopper, also known as "Cotton Candy Lover" Chopper,[6] is the doctor of the Straw Hat Pirates and one of the Senior Officers of the Straw Hat Grand Fleet.[2] He is the sixth member of the crew and the fifth to join, doing so at the end of the Drum Island Arc. He was temporarily forced to join the Foxy Pirates during the Long Ring Long Land Arc, but was quickly returned to Luffy's crew.

Chopper is a reindeer that ate the Hito Hito no Mi, a Devil Fruit that allows its user to transform into a human hybrid or a human at will. He was taught how to be a doctor on Drum Island by his two parental figures, Doctors Hiriluk and Kureha. His dream is to one day become a doctor capable of curing any disease and wants to travel all across the world specifically in the hopes of accomplishing this dream.

He gained his first bounty of 50 after the incident at Enies Lobby due to being mistaken for the crew's pet. After the Dressrosa Arc, it was increased to 100, then to 1,000 following the Raid on Onigashima.[2]