"That Evil Prince" (not to be confused with "The Evil Prince," another song by Frank Zappa) is a dialogue track from the 1984 pseudo-musical Thing-Fish. The short scene features Harry (Terry Bozzio), his wife, Rhonda (Dale Bozzio), and Thing-Fish (Ike Willis). The two yuppies are impressed by the Evil Prince's typical Broadway elegance. Their longing for legitimate theater obscures the fact that the man is responsible for the Mammy Nuns' horrible mutation, something the main character quickly points out. The track ends with a forced twist in the dialogue to allow a segue into "You Are What You Is."
The interest of "That Evil Prince" does not reside in the scene it contains, but in the background music. The delicate melody faintly heard is a proto-version of what will become the Synclavier piece "Amnerika" on Civilization Phase III.