Tortimer is the mayor of the town you move into in the Animal Crossing games. On holidays, he gives you different presents depending on what holiday it is. For example: In AC for GameCube, if it's Halloween, he'll give you "Katrina's Tent." In ACCF, if it's Groundhog Day, he'll give you a "Resetti model." He is a wise old tortoise. In Animal Crossing City Folk, there is a rumor is that his shell is fake.
In Mushroom Kingdom Hearts II: The Other Land, Tortimer is the mayor of Treehut. When Bly comes to Treehut through a Portal of Darkness and asks Sass about the location of the Keyhole, Tortimer tries to lead him away by giving him wrong directions. After Bly leaves, Sass asks Tortimer what the Keyhole is. Tortimer changes the subject and leaves. When Bly returns, after realizing he had been fooled, he brings a platoon of Heartless and threatens the Mayor that he'll have the Heartless swallow the world into darkness if he doesn't tell him the truth. Tortimer claims he doesn't know it's true location, and Bly has the Heartless attack him. After Sass uses the Keyblade to fight off the Heartless, Tortimer brings her to the Wishing Well, the true location of the Keyhole. He asks Sass to seal it with the Keyblade, but it's too late. The Heartless swallow the world in darkness and Bly gains what he was searching for.