Mad Hatter?

The Hatter (called Hatta in Through the Looking-Glass) is a fictional character in Lewis Carroll's 1865 book Alice's Adventures in Wonderland and its 1871 sequel Through the Looking-Glass. He is often referred to as the Mad Hatter in adaptations and pop culture, though this term was never used by Carroll. The phrase "mad as a hatter" predates Carroll's works. The Hatter and the March Hare are described as "both mad" by the Cheshire Cat in Alice's Adventures in Wonderland.