The Game of Thrones actor will voice the goat Dr. Dillamond, a professor of history at Shiz University, in the movie adaptation of the famous Broadway musical. In the story, Dr. Dillamond warns Cynthia Erivo's witch Elphaba about rising dark forces that threaten the speaking animals of Oz, including himself. In addition to Erivo, the two-part Wicked adaptation also stars Ariana Grande as Glinda as well as Jonathan Bailey, Michelle Yeoh and Jeff Goldblum, among others. The stars joined director Jon M. Chu onstage at Caesars Palace to present new footage.