Inspector Dix is a persistent Scotland Yard detective depicted as a dark brown dachshund. Originating from Jules Verne's Inspector Fix, he serves a similar narrative function. Dix relentlessly pursues Willy Fog across the globe, utterly convinced Fog robbed the Bank of England. His singular mission is to secure proof of Fog's guilt, delay the group's progress, and execute an arrest warrant once it arrives from London. Though antagonistic, Dix operates from a strong sense of duty and honor, frequently expressing outrage at Fog's expenditure of what he deems stolen funds.

He exhibits exceptional excitability and a penchant for comical verbal blunders, such as declaring himself a "pursuit officer in police of the criminal who robbed the Bank of England." Another recurring trait is his consistent misnaming of Rigodon as "Brigadoon" or similar variations, stemming from the original Spanish version's use of "Tontorron."

Dix is partnered with Constable Bully, a bulldog. Their dynamic features Dix displaying frequent frustration and occasional mistreatment of the timid Bully, particularly over Bully's clumsiness, travel sickness, and complaints about the arduous journey. Despite this abrasive exterior, Dix demonstrates underlying care for his partner. Both express genuine concern and sorrow when Tico falls seriously ill.

His efforts to apprehend Fog are consistently thwarted within the main series narrative, with no significant character evolution or resolution of his pursuit. His motivations and methods remain unchanged. Beyond the primary 26-episode series, no spin-offs, movies, OVAs, or sequels—including "Willy Fog 2"—provide additional development, backstory, personal life details, or exploration of his activities outside the around-the-world journey.