The Hatter is a fictional character initially encountered at a tea party in Lewis Carroll's Alice's Adventures in Wonderland and later again as "Hatta" in the story's sequel, Through the Looking-Glass. He is popularly referred to as "The Mad Hatter," but is never called by this name in Carroll's book—although the Cheshire Cat does warn Alice that he is mad, and the Hatter's eccentric behavior supports this. (Likewise, the chapter in which he first appears, "A Mad Tea-Party," is often called "The Mad Hatter's Tea Party").
He has been portrayed on film by Edward Everett Horton, Sir Robert Helpmann, Martin Short, Peter Cook, Anthony Newley, Ed Wynn and, in a music video, by Tom Petty. The Hatter explains to Alice that he and the March Hare are always having tea because, when he tried to sing for the Queen of Hearts at a celebration of hers, she sentenced him to death for "murdering the time," but escaped decapitation. He comes to the conclusion that time itself was indeed "murdered," he and the March Hare continue to have tea as though the clock had truly stopped.
His tea party, when Alice arrives, is characterized by switching places on the table at any given time, making (along with the March Hare) somewhat short, personal remarks, asking unanswerable riddles and reciting nonsensical poetry, all of which eventually drive Alice away. He appears again as a witness at the Knave of Hearts' trial, where the Queen appears to recognize him as the singer she sentenced to death, and the King also cautions him not to be nervous "or I'll have you executed on the spot." When the character makes his appearance as "Hatta" in Through the Looking-Glass, he is in trouble with the law once again. This time, however, he is not necessarily guilty: the White Queen explains that quite often subjects are punished before they commit a crime, rather than after, and sometimes they do not even commit it at all.
He is also mentioned as being one of the White King's messengers, and the March Hare appears as well as "Haigha," since the King explains that he needs two messengers: "one to come, and one to go." Sir John Tenniel's illustration also depicts him as sipping from a teacup as he did before in the prequel, adding weight to Carroll's hint that the two characters are indeed the same.