The Mad Hatter is a fictional character from Lewis Carroll's novel, Alice's Adventures in Wonderland. He is known for his eccentric personality and whimsical behavior, often engaging in nonsensical conversations. The character is typically depicted wearing a large hat, which is a symbol of his madness and creativity. In the story, the Mad Hatter hosts a tea party with March Hare and Dormouse, where time seems to stand still. His character has become iconic in popular culture, representing the theme of absurdity and the challenges of logic in a fantastical world.