General Guph mentions that Dorothy and Scarecrow are to prepare for the Nome King's birthday. For generations, the Nomes have been ruled by the Nome King, who oversees the mining of magic from the rocky caves of the Nome Kingdom. You can read more about the Nome King in L. Frank Baum's book, "The Emerald City of Oz".
The name Van Dyne Blvd., location of Dr. Scurvy's office, is inspired by "Edith Van Dyne," one of L. Frank Baum's many pseudonyms he used when writing non-Oz books.
Patchwork mentions that he was brought to life by Dr. Pipt, who used a magical substance called "the Powder of Life" to animate his patchwork body. You can read more about Dr. Pipt in L. Frank Baum's book, "The Patchwork Girl of Oz".
Cyra combines Halcyonite with Quellium to make a potion to suppress West's powerful inner magic. Halcyonite and Quellium are calming magical elements that, when combined correctly, can suppress magical ability.
One of the nomes is named Wamego; Wamego is a real town in Kansas and is the home of the Oz museum.