File:Brook Smoking in Movie 10.png

Source of Image and Excerpts of Brook's Character
The following image is from the One Piece Film (#10): Strong World (Chapter/Episode 0), which happens to be the first movie release including Brook as part of the Straw Hat Pirates, and the movie plot was written by One Piece mangaka/manga creator Eiichiro Oda himself.

=
(This will begin a brief bio of Brook's character; please refer to Brook's page by clicking on his linked name for a more in-depth explanation of his character and his roles in other canonical situations.)=====

Brook, a resurrected musician with the stage name "Soul King" that uses Ittoryu ("One Sword Style") with his trusted blade Soul Solid, is the member of the Straw Hat Pirates and joins the crew to carry out and complete a personal mission for his former crew as they all, excluding Brook, have passed. He was Second Captain and musician of the Rumbar Pirates when he first met Laboon, who happens to be the exact same whale the Straw Hat Pirates encountered at the Reverse Mountain area of the Grand Line, and Laboon began to love the music Brook played. and replay a tune of old on a Tone Dial to fulfill the Rumbar Pirates' promise to rendezvous with Laboon for one last time, as the entire Rumbar Pirate Crew put the effort of a lifetime to have the song recorded perfectly, as the crew members dropped one by one, with Brook falling last.

The reason Brook appears as a living skeleton when the Straw Hat Pirates come across the Rumbar Pirate ship, is because he ate the Yomi Yomi no Mi (Revive-Revive) Devil Fruit

Brook is known for having a distinct comical personality with his clothing, mannerisms, expressions, humor and talent with instruments (sword included) showing roots from influences such as Ozzy Osbourne, Jimi Hendrix, Slash, and other popular musicians. What each of these artists had in common, and popular culture is aware of this commonality, is drug use outside of tobacco and alcohol.

"Is it realistic to claim that Brook is smoking cannabis, an illegal drug, instead of tobacco?"

As a pirate with a unique situation because of his resurrection and second life as a skeleton, losses of his own shadow and former crew, desired recruitment by the Straw Hat Pirate Crew's founder and captain Monkey D. Luffy, and rememberance of the Rumbar Pirates' promise to Laboon, Brook after the Straw Hats defeated Gekko Moriah, Shichibukai at the time, at Thriller Bark.

Brook has to maintain his bone strength, not 100% confirmed because of the United States federal government disallowing former scientific studies

The Japanese cannabis prohibition laws are listed in the Cannabis Control Law, which is documented in Japanese kanji, and The way Brook was holding the cigarette can be interpreted as a more common technique for cannabis cigarettes than tobacco cigarettes. smoking cannabis expresses a deviance from the government's (the Marines/Navy's) viewpoints.