Mud Kingdom

The Mud Kingdom is the home of the MudWings, who thrive in the swampy, humid climate. It is on the back of Pyrrhiaunder the Sky Kingdom's wing and next to the Rainforest Kingdom and the Kingdom of the Sea. It was described by Turtle as "dreary, swampy, and bog-riddled." Queen Moorhen currently rules the Mud Kingdom. There is also a delta(and maybe more) and a ravine/ fissure mentioned in the first book.