From Nookipedia, the Animal Crossing wiki
Gaston (モサキチ, Mosakichi) is a cranky rabbit villager in the Animal Crossing series. His initial phrase and name suggest he is French, or from French origin. His name, Gaston, is a male French name and his initial phrase, "mon chou", is a play on words with "chou chou", a term of endearment. "Mon chou" on its own translates to "my cabbage". Gaston's photo inscription reads as "Sacre Bleu!", further establishing his character as a Frenchman.
Gaston is a yellow rabbit with blue inner ears, a small orange nose, a big bushy mustache, brown feet and white paws. His eyebrows are pointed down, giving him a very serious, profound stare.
Below is a brief description of the cranky personality. For more information, click here.
As a cranky villager, Gaston will appear mature compared to other male personality types. This will make him appear rude and belittling when talking to other villagers, including the player. Despite this, he will learn to confine in the player, considering them his only friend. He will enjoy the usual hobbies, but not for competition, but for relaxing and peaceful reasons of calm and tranquility. He will find it difficult to socialize with peppy villagers, who he will appear rude behind their backs to. He will get along with normal and snooty villagers, as well as other cranky villagers, who he will share deeper conversations with. He will, on occasion, annoy a normal villager, usually when being mean about something or someone. When he is sick, he will insult the illness and act delirious, thinking the player is his mother.
In Animal Crossing Gaston's house has a Tiki Torch, Haz-Mat Barrel, Sandbag, Speed Bag, two weight benchs from the Boxing Theme, Hamster Cage and Science Table from the School Theme, a Reel-To-Reel which plays K.K. Dirge. Lastly he got a Piranha and Giant Catfish. His wallpaper and carpet are Basement Wall and Basement Floor which are obtainable from Wendell and Saharah.
Names in other languages
Gaston appears on the front case of the original Animal Crossing right above the player looking out a window.