Wicked dives into the personal life of The Wizard of Oz‘s Wicked Witch of the West, and even her name is a subtle Easter egg to the original story. The 2024 movie is based on the Broadway musical of the same name, which is itself based on the 1995 novel by Gregory Maguire. The author did the work of diving a little deeper into the world of Oz, providing a prequel story that gave audiences a look at everything from the villain’s perspective. Maguire ultimately named the Wicked Witch Elphaba, and this same name has carried over into the Wicked musical and, of course, the movie.

https://screenrant.com/wicked-witch-elphaba-name-easter-egg-factoid/