From Nookipedia, the Animal Crossing wiki
The player, also known as the villager, playable character, or boy/girl, is a term used for the playable human character in the Animal Crossing series. The player may be either a boy or a girl; the differences in all games are largely cosmetic and with slight variations to some dialogue whenever the conversation becomes gender specific.
OverviewPlayers, like the main villagers, are short and stubby (in Animal Crossing: New Leaf they are taller and less stubby). The largely-physical differences may become blurred even further because Harriet allows the player to get haircuts of the other gender if one has had all hairstyles of one's gender from her. Kicks will also allow the player to get shoe shine colors of the opposite gender after enough shoe shines have been bought, however there are several unalterable differences. In Animal Crossing: New Leaf the player can buy and wear any shoes regardless of gender from Kick's shop.
The female character will always wear a dress, while the male character will always wear shorts, and the female character's default hat is a cone-shaped "princess cap", while the male character's resembles a spiked Viking helmet. These hats are used in Animal Crossing as the only hairstyle or head wear. In New Leaf, however, the player can wear clothes designed for the opposite gender and wear different kinds of hats.
Even though players are not the only humans, they are the only human children as it is assumed Mom and Dad, who send letters occasionally, are also human. Players will always have an in-game "mom" and in spite of Mom referring to childhood events and the home that the player once lived in and occasionally sending presents in the mail, there is no indication of any real back story to the human character(s).
Only one player from each town may be active at any given time, although in Animal Crossing: Wild World, Animal Crossing: City Folk, and Animal Crossing: New Leaf, visiting players (Over Wi-Fi) from other games are allowed in town at the same time.
Also, players rarely talk aside from answering questions, remarking about an accomplishment, and talking in Happy Home Showcase.
In each game, the player's face is determined by a series of questions that the introductory character asks.
In Animal Crossing
In Wild World
In Animal Crossing: Wild World, Kapp'n asks the player a series of three questions while driving him or her to town at the beginning of the game in his taxi in order to determine the player's face style.
In City Folk
In Animal Crossing: City Folk, Rover asks the player a series of three questions while riding with him or her to town at the beginning of the game in Kapp'n's bus in order to determine the player's face style.
In New Leaf
The player models in Animal Crossing: New Leaf are taller and presumably older. The player can now change their pants, skirts, shoes and socks in addition to their top. Their face will be determined, like other games, while on the train by Rover.
WarioWare: Smooth Moves
In WarioWare: Smooth Moves, one of the microgames involves the player taking control of a character, the gender corresponding to that of the controller's. The player must pull the Wii Remote up at the correct time to catch a fish.
In Super Smash Bros. Brawl, a number of human characters appear in the background of Smashville. Both the male and the female players are available as stickers, while the male character is available as a trophy which is simply named "Boy."
Super Smash Bros. for 3DS/Wii U
On June 11, 2013, Nintendo revealed their new Super Smash Bros. video game for the 3DS and Wii U at Electronic Entertainment Expo 2013, featuring the "Villager" (むらびと, Murabito) as a new playable character. The Villager is a boy with brown hair, wearing a red shirt with a light-blue number "1" printed on the front. The Villager's in-game moves include the ability to attack other players using a net, trapping them in pitfalls, and chopping down trees to cause damage. He is based on the default appearance for male characters from the first five installments of the Animal Crossing series. Other seven skins are available, each with a different appearance, and alternating genders between male and female for a total of four skins representing each gender.
Two genders of villagers, based on their default appearances from New Leaf, have made a guest appearance in the Wii U game Mario Kart 8 as part of a downloadable DLC pack (along with Isabelle and Dry Bowser from the Mario series), where they again are known as Villager. They do not make voice effects, but they will make a variety of emotions and the sound effects associated with them depending on the situation. Both villagers are classified as a middleweight, indicating average stats. Both villager types weigh slightly less than Mario and Luigi, but the male villager weighs more and has higher speed than the female villager, while the female villager has better acceleration, handling, traction, and off-road stats.