The Mad Hatter was rumored to have once lived in a tea room at the top of the Frobozz Magic Well in the Alice Area of the Dungeon of Zork, and died from advanced mercury poisoning. He left behind his tea table with a collection of cakes frosted with various latters. These cakes, which were used/consumed by the Second Dungeon Master, included a green "Shrink" cake, a red "Evaporate" cake, an orange "Explode" cake, and a blue "Enlarge" cake.

SOURCE(S): Zork II (allusions in room description, invisiclues)