Froboz Mumbar is the author of the well-known books, "The Great Underground Empire: A History", published in 896 GUE by the Frobozz Magic Book Company (This book is the source of many historical details quoted by this Encyclopedia), and "The Early Myths of Frobozz," published in 880 GUE.

Mumbar was the one to discover the so-called Royal Diaries of Zilbo III in the Largoneth Archives shortly after 860 GUE. Although he carefully analyzed the diaries, still today they have been the matter of some controversy in detailing the backdrop of the 659/660 GUE New Year's Revolt. He also believed that Wurb Flathead's ineptitude was the only reason the empire collapsed at all.