His name is French, and may refer to Jacques Cousteau (possibly a joke on his jock personality). His initial phrase, "oui oui", is French for "yes yes". His species relates to the common French stereotype in which frogs' legs are a type of food.
Despite his appearance and initial phrase in English-language localizations of the game, his name in Japanese means "spring roll", a traditionally Chinese dish. His house also has an east-Asian theme to it.
Cousteau is a yellow frog with reddish-brown spots. He has a black mustache and closed eyes that give him a joyful appearance. His hands are white and his feet are reddish brown. Prior to New Horizons, he initially wears the rally tee.
Personality
Below is a brief description of the jock personality. For more information, click here.
Cousteau has a jock personality and has a great interest in sports and bodybuilding. Jock villagers are hyperactive and motivated, but often come across as self-centered and dense. As a jock villager, Cousteau is very interested in his hobby, and may compete against the player at catching bugs and fish. Jock villagers get along with peppy, cranky, and sisterly villagers, but conflict with the laid-back lifestyle of lazy villagers. Snooty villagers may also be difficult to get along with for Cousteau.
In New Leaf, Cousteau's house is a bit different from the past games. It now has an Asian restaurant feel to it, due to the lazy-Susan table, salad bar, and revolving spice rack. He still has exotic furniture, such as the exotic table, and two exotic screens. He also still has the exotic rug and exotic wall, as well as a reel-to-reel playing Imperial K.K.
Cousteau is a famous deep-sea diver in the village. But when he's not hunting down some rare species of Coelacanth or Barred Knifejaw, he's cooking up a gourmet meal for his family and friends.