Professor Genius first appears as a supporting figure in Winsor McCay’s *Little Nemo in Slumberland* under the name "Dr. Pill," differing in both demeanor and design from later portrayals. The 1992 animated film *Little Nemo: Adventures in Slumberland* reimagines him as a pivotal advisor to King Morpheus, charged with managing royal affairs, mentoring Princess Camille, and orchestrating Nemo’s dirigible-guided arrival to Slumberland. Combining erudition with moments of shyness, he mentors Nemo while enforcing protocol, though his cautious tendencies give way to bravery when aiding the group’s mission to rescue the king from the Nightmare King. During their perilous journey to Nightmare Land, he offsets Flip’s impulsivity with grounded reasoning, offering both strategic aid and quiet empathy. His real-world identity as a circus organist reflects Nemo’s subconscious reshaping of parade spectators into Slumberland’s denizens, cementing his role as a conduit between waking life and dreams. The character exhibits punctuality, thrives in orderly settings, and reveals an unexpected penchant for dance during Slumberland’s celebrations. While excluded from adaptations such as *Little Nemo: The Dream Master*, he makes fleeting appearances in the arcade game’s opening and ending sequences. No expanded backstory or additional narrative roles beyond these core functions exist in official media.