Thwack of Mareilon classified the Moss of Mareilon in 843 GUE. In 845 he published the book, "The Biological and Thaumaturgical Properties of Mareilon Moss."

Some apocryphal reports of the day's events note that Thwack of Mareilon was actually in the audience to witness King Barbawit Flathead's comic routine, and was in fact more than somewhat inspired by the pale greenish color of the fluids gushing from the injured monarch's ears, eyes and nose, after the king himself was pulled off the stage and attacked by the angry mob, barely escaping with his life. Whether this odd revelation was in fact the breakthrough that led him to the correct classification of the Moss of Mareilon, we will in all likelihood never know.