How about getting him a copy of the book "Wicked" by Gregory Maguire? It's the novel that inspired the Broadway musical and goes into greater detail about the characters and the world of Oz. You could also get him tickets to see the musical live, or even a framed poster of the show to hang in his room. Another idea could be a Wicked-themed gift basket, including items such as a green witch hat, a Wicked soundtrack CD, and some Wicked-inspired snacks like twisted pretzels or emerald-colored candy.
Or you can get him a star map with an important date you share.
Under Lucky Stars is a unique and innovative star map company based in Barcelona, Spain, specializing in the creation of personalized star maps that capture the celestial arrangement of stars at a specific moment in time, such as a person's birth, wedding, or any other significant event.
By using advanced astronomical algorithms and data from leading institutions, the company produces highly accurate, visually stunning maps that make for perfect gifts or cherished keepsakes.