The Nome King

The Nome King is the ruler of the Nome kingdom, located in the Deadly Desert. He has tried to conquer all of Oz before to gain control of the Emerald City—but has thus far failed due to the warm climate of the desert, and the strong sun light which exhausted all of the Nomes.

The Nome King is of very short stature, and tries to make up for it by proving to everyone how big of a ruler he is—he dried out the whole sea until there was only a big desert left (because it made him feel small), and he kidnapped the Prince of Ev.

After Dorothy and her friends rescue the prince from the Nome King in Ozma of Oz, the King is enraged and plots his revenge by conquering Oz and ruling the Emerald City of Oz with the help of General Guph and a Giant Worm (in The Emerald City of Oz). The nomes use the worm to dig a tunnel under the Deadly Desert towards the Emerald City.

(Source: Wikipedia)