The Imaginarium of Doctor Parnassusfits into the Fantasy genre, being almost a classical fable with fantastic elements and events that could not occur in "reality." Like many fantasy works, the film is defined by a sense of wonder, oddities, inhuman creatures and actions, and a strong theme of morality.
By showcasing strange and wondrous places and beings, director Terry Gilliam uses the fantasy genre to represent his own career and the artist's fear of death. The central theme of the movie, a Deal with the Devil, is a classic fantasy trope, appearing in stories from Washington Irving to Isaac Asimov. Events throughout the film also have a fantastic effect, with a magic mirror, the physical transformation of the main character (due to Heath Ledger's death during production), and moral dilemmas appearing both overtly and metaphorically.