Villain of the Week- Ruggedo, AKA Roquat, the Nome King

From Wiki- The character called the Nome King is originally named Roquat the Red. Later, he takes the name Ruggedo, which Baum first used in a stage adaptation. Even after Ruggedo loses his throne, he continues to think of himself as king and the Oz book authors politely refer to him that way.   In Baum's universe, the Nomes are immortal rock fairies who dwell underground. They hide jewels and precious metals in the earth, and resent the "upstairs people" who dig down for those valuables. Apparently as revenge, the Nome King enjoys keeping surface-dwellers as slaves—not for their labor but simply to have them.  The Nomes' greatest fear are eggs. Upon seeing Billina, Roquat is terrified, declaring that "Eggs are poison to Nomes!" He claims that any Nome who comes in contact with an egg will be weakened to the point that he can be easily destroyed unless he speaks a magic word only known to a few Nomes. back to me: 

I did not remember Ruggedo had a different name originally.  He drank "the waters of oblivion" in the fifth book, so taking a new name isn't surprising.  I need to reread the books again.