From Nookipedia, the Animal Crossing wiki
Saharah (ローラン, Rōran, Roland) is a camel in the Animal Crossing series that trades in rare carpets and wallpaper to the player. She has a different service in each Animal Crossing series game. Her name comes from the Sahara Desert in Africa. One of her exclusive carpets is even called "Saharah's Desert".
In the original Animal Crossing, Saharah makes her living selling rare and exotic carpets from faraway lands. Like most of the game's other special characters, Saharah sells items that cannot be found anywhere else. She does, however, have a different way of doing business than Tom Nook; she accepts trade-ins. In order for the player to get their hands on one of her carpets they must trade in one of their carpets along with some money, starting at 3,000 Bells. Her prices double each time they buy a carpet and prices can get pretty steep. They player should not be stingy because she may have the carpet they need to complete a certain series or theme. In Animal Crossing she also retains her Japanese Male voice.
In Animal Crossing: Wild World, Saharah returns and this time she gives rare wallpaper, taking over from Wendell. Instead of her trade-ins, she asks the player to deliver carpet and wallpaper to special characters such as Blathers, the Able Sisters, Tom Nook, Pelly and Phyllis (but never to villagers), similar to the way that the player works for Tom Nook earlier in the game. In return, she will give the player a choice of either rare carpet or wallpaper.
She plays a part in the Golden Axe Trading Event, which involves the player trading various items to other special characters and hopefully get given a Golden Axe. When the player gets to know Saharah, she will talk about how she "longs for a turban". When given a turban, she will either give the player a red vase or a massage chair which can then be used further on in the event, by trading to Tortimer.
In Animal Crossing: City Folk, Saharah returns and once again accepts trade-ins. Though the player does not have to pay, she asks for old wallpaper or carpet from other villagers around town, and usually only one or two will have them. If the player saves three of these old wallpapers or carpets every time she visits, she will give the player a rare wallpaper or carpet. If they try to give her a wallpaper or carpet from their home or Tom Nook's Store, she will say that it is "still lovely!" but not accept it.
In Animal Crossing: New Leaf, Saharah returns and will sell the player a new wallpaper and carpet for 3,000 Bells. When the player meets her, she asks them to lead her to their house. She then leaves the player out of the house temporarily while redecorating the first floor room with a new carpet and wallpaper. Finally, she emerges and gives the player the old carpet and wallpaper. She can install 'normal' walls and carpets as well as rare Saharah originals.