From Nookipedia, the Animal Crossing wiki
Tortimer (そんちょう, Sonchou, コトブキ, Kotobuki), is an elderly tortoise and the mayor of the town the player moves into in the Animal Crossing series (excluding Animal Crossing: New Leaf, where that role is given to the first player that moves into the town). He has appeared in every installment in the Animal Crossing series except for the original game, Dōbutsu no Mori. He also appeared in Dōbutsu no Mori (film). His name is a portmanteau of 'tortoise' and the human name 'Mortimer'. His laugh is 'heh heh hoorf'.
During town events, Tortimer can often be found outside celebrating, and may give away holiday-specific items. In Animal Crossing: Wild World and Animal Crossing: City Folk, he can be seen napping in the back of the Town Hall when there are no active events. In Animal Crossing: New Leaf, Tortimer has retired from the role of mayor and now lives on Tortimer Island where he works as a tour guide.
Tortimer seems to have a large ego, according to Dōbutsu no Mori (film), to the extent of having his own cult of personality, though he is its only follower. This is supported in the games, since during festivals he always seems to remind the player of his authority, such as during Nature Day in City Folk, where he boasts the slogan 'Mother Nature and Father MAYOR'.
 Role in Events
Tortimer is a very old tortoise and is the mayor of the player's town. At any events, like the Flower Festival, he will stand outside the town hall to explain the competition. At the end of the competition he will give a shiny gold trophy to the winner. At other occasions like Bonfire Night, he will give you a free sparkler. At New Year's he will give out a shirt and a party popper. At Fireworks Night he will give a Roman Candle and a Sparkler. The events he appears at are spread out at all different times of the year. He appeared on Bonfire night only in Dōbutsu no Mori e+.
Occasionally, Tortimer talks about his life previous to becoming mayor. He talks about being an expert gardener and once had a wife, Mrs. Tortimer, though she is believed to have died tragically. Some villagers speculate that he became incredibly rich on the turnip market, while others believe he gained money illegally and used it to build the town hall. This is backed up by the fact that there are no taxes in the player's town, and that Tortimer himself never has to face election. Also, according to the gossip of villagers in City Folk, his shell might be fake.
 Other Appearances
Tortimer appears as a trophy and in the background of the Smashville stage.
 Names in other languages