Growleywogs are wicked, disagreeable creatures who live outside the Land of Oz.
They are of remarkable size, but are all skin, bone and muscle, there being no meat or fat on their bodies at all. Their powerful muscles lay just beneath their skin like bunches of tough rope.
Growleywogs are disagreeable and overbearing, and are unsociable even among themselves. They are ruled by the Grand Gallipoot.
The Growleywogs joined the Nomes in a plan to conquer the Land of Oz alongside the Whimsies and the Phanfasms. They were promised twenty thousand Oz people as slaves, but they planned to loot the kingdom and perhaps enslaves the Nomes as well.
As they invaded the Emerald City from a tunnel that is dug under the Deadly Desert, Ozma filled the tunnel with a large amount of dust. The Growleywogs thirstily drank the Water of Oblivion and forgot their wickedness. They were sent back home as innocent as children. (The Emerald City of Oz)