The Time Dragon Clock
Originally an important part of the book Wicked, a traveling puppet show called the Clock of the Time Dragon makes an appearance at the start of the Broadway show under the name the Time Dragon Clock. However, in the film, it is only briefly mentioned when Glinda (Ariana Grande) confirms Elphaba's (Cynthia Erivo) death to the citizens of Oz.
Elphaba's Childhood
While the stage version does touch on Elphaba's conception and birth, there is no flashback showing her as a young child. However, the film shows viewers what her life was like growing up, and even gives a glimpse at her powers from a young age. The movie also introduces the character of Dulcibear (Sharon D. Clarke), a talking bear who is present when Elphaba is born and takes responsibility for raising her after her father (Andy Nyman), the governor of Munchkinland, is horrified that she's green. Dulcibear also provides a backstory for why Elphaba is so concerned about animals being removed from society and losing the ability to speak, a major plot point in the film and the musical.
Elphaba's Introduction to Shiz University
In the Broadway musical, Elphaba is already enrolled at Shiz University as a way to help take care of her sister Nessarose (Marissa Bode). In the film, she is merely there to drop her off, but when Madame Morrible (Michelle Yeoh) sees her display of power, she insists that Elphaba enroll. The rest unfolds much the same, with Glinda accidentally volunteering to be Elphaba's roommate, with the musical version explaining that Elphaba's room assignment must have fallen through the cracks.
Doctor Dillamond and the Animal Freedom Fighters
In both the musical and the movie, Doctor Dillamond (voiced by Peter Dinklage in the film) is a talking goat and the history professor at Shiz who makes the students aware of the ongoing plot against animals throughout Oz. While the film introduces audiences to several other talking animals who appear to be part of an animal resistance movement, they do not appear in the musical. On stage, the song "Something Bad" takes place in Doctor Dillamond's classroom, while on screen it's sung by him and Elphaba in his private quarters.
Elphaba and Fiyero's Meet Cute
Both the musical and the movie include a love triangle between Glinda, Elphaba and Fiyero (Jonathan Bailey). However, Fiyero's introduction and how he meets Elphaba do differ from stage to screen. In the show, his carriage almost runs her over when he is dropped off at Shiz by his servant. In the movie, he almost tramples over Elphaba in the woods while riding his horse near the university, with Fiyero joking that they didn't see her as she blended in with the greenery.
The Little Lion Cub
After Doctor Dillamond announces that he is being let go from Shiz, a new professor takes over and shows off new cages that have been designed to hold animals—with his example housing a sad lion cub. Elphaba is furious and, in the stage show, causes the students and professor to start moving uncontrollably as she and Fiyero rescue the cub and take him to safety. In the movie, she ends up putting all of them to sleep instead by using poppies (an Easter Egg for the original 1939 film The Wizard of Oz, in which she puts Dorothy, the Scarecrow, Tin Man and Cowardly Lion to sleep in a field of poppies).
Off to the Emerald City
There's one small change as Elphaba heads off to meet the Wizard (Jeff Goldlbum) in the film: Her father comes to the train station, where Nessarose introduces him to Boq (Ethan Slater). However, her father does not come to say goodbye in the musical.
The Tale of the Grimmerie
The movie provides more information on the Grimmerie, an ancient book of spells written in a language that is lost to modern-day Ozians. So, while the movie version does not feature any full new songs, it does feature a new section added to "One Short Day. The movie's extended version adds to the legend of the Wizard, and claims that he is the only person who has been able to read the Grimmerie, fulfilling an Ozian prophecy many had been waiting for (which we later learn is not true as he cannot read it, but Elphaba can.)
The Original Witches Return as New Characters
Not only is "One Short Day" the song that was changed the most from the stage to the screen, but it offers another surprise as well. The new section in the movie is sung by special guest stars: Broadway's original Elphaba and Glinda, Idina Menzel and Kristin Chenoweth. The duo are credited as Wiz-O-Mania Super Stars, playing characters that do not appear in the stage version, but provide fans of the musical a double dose of nostalgia as they interact with Erivo and Grande in the Emerald City.
The Not-So-Wonderful Wizard of Oz
In both versions of Wicked, the Wizard starts off by charming both Elphaba and Glinda. However in the movie he does it with the aid of a giant model of Oz, saying he plans to build a road that will lead its citizens to the Emerald City. He even lets Elphaba and Glinda pick the color of said road, leading to the creation of the famed Yellow Brick Road.
Elphaba Defies Gravity
While there are no huge changes to the act one climax (and ultimately the film's ending), Elphaba's big musical number does get stretched out in the film, and includes a moment where she sees a vision of a younger version of herself, which spurs her on to fly away and leave the Wizard and Glinda as she makes a new name for herself. The stage play doesn't include such a flashback.