His grandfather, who was a friend of the cartoonist Roy Crane, had a large collection of old Sunday comics, which were an early source of inspiration to Millionaire.

Returning to the U.S. in the early '90s, he moved to Brooklyn, where he began drawing a regular comic strip, Medea's Weekend, for the Williamsburg newsweekly Waterfront Week.

One night at a local bar, the Six Twelve, Millionaire drew "a cartoon about a little bird who drank booze and blew his brains out"[6] on a napkin – the origin of his best-known character, Drinky Crow.

Eventually the alternative newsweekly New York Press asked him to draw a weekly strip, and in 1994, Maakies debuted in its pages.

His linework resembles that of Johnny Gruelle, whom he cites as one of his main sources of inspiration, along with Ernest Shepard and "all those freaks from the twenties and thirties who did the newspaper strips";[9] many of Millionaire's admirers adduce a similarity to the work of E. C. Segar in particular.

The nautical settings of much of Millionaire's work draw inspiration from his childhood memories of his grandparents' artwork and seaside home, as well as the novels of Patrick O'Brian, of which he is an avid reader.

"[11] He has said his unusual surname is an Old French word meaning "a person who owns a thousand serfs,"[6] but the origin of the name "Tony Millionaire" is a character in an episode of the 1960s TV series I Dream of Jeannie.