This book is not yet written, but will be as soon as I finish writing my young adult novel Max Ammo: Dead Planet. Thundar the Wicked is book three in my series the R.U.M.P. Chronicles.
For a time, our mighty king Thundar believed his curse of R.U.M.P. disorder was well behind him. But one day he began having feelings that were foreign to him; feelings of anger, deceit and even hatred. His friends, especially his most trusted adviser, Grizzby, began to notice that something was not right with their king. Somehow, he was becoming Thundar the Wicked.
You can learn more about this series at the following links: