Seymour was one of many long lost cousins of a family of fungi living in the ear of the Great Brogmoid which holds up the world. These lost cousins were found between the toes of the Great Brogmoid who stands on the top of Mount Foobia. Other cousins include Sherman, Irving, Sammy, Myron, Boris, Melvin, Lester, Julius, Ricardo, Omar, and Barnaby. In 883 GUE, the First Dungeon Master returned one of these to the ear fungi family, in which a joyful reunion followed. It is unknown if any of the rest were ever reunited.

SOURCE(S): Zork Zero