In 1951, Disney created an animated version of the original story; they changed the name to 'Alice In Wonderland.' Much like the original story, it was based on Alice, falling asleep, and dreaming of a Wonderland. That's where The Mad Hatter comes in. The Mad Hatter is nothing but a character of Alice's imagination. He first appears at an unbirthday tea party, but later shows up when she is running from the Queen Of Hearts, before she wakes from the strange dream. The Mad Hatter is my favorite character, because of how random he is, and how well he fits into the Wonderland theme. In the Disney version of this movie, he is considered to be 'mad.' In my opinion, he is not as mad as he is eccentric. He offers Alice tea, makes her move to a different cup, asks Alice to tell him about how she found Wonderland, and cuts her off with: "Why is a Raven like a Writing desk?" Then he tries to fix The White Rabbit's watch...
Mad Hatter's guide to: Fixing a watch that is two days slow. Problem: Watch is two days slow, and full of wheels. Ingredients: Tea, Two Spoons, Jam, Butter, Lemon. (Whatever you do, Do not add Mustard!) Instructions: Put all of the ingredients inside of the slow pocket watch. Close the watch. Cut around the edges of the watch, using a knife. Let go of the watch.
Oh...oops...You should probably go get a mallet now, because that was not how to fix a watch. That, is the way to make a mad watch, and everyone knows the only way to fix a mad watch, is to use a mallet... Hopefully, you keep a spare mallet close by, in case of a mad watch. You should keep one close... You're in Wonderland after all!
For more on the Hatter, I suggest you go to the Fun Facts Category.