On the Celtics' logo, the leprechaun has a cane in his left hand.
The leprechaun is Lucky, the Boston Celtics' longtime mascot. In the familiar circular logo, Lucky spins a basketball on the index finger of his right hand while holding a cane in his left. The cane is also commonly described as a shillelagh, an Irish-style walking stick.
The image connects the team to Boston's Irish-American identity and to the word "Celtics." Cartoonist Zang Auerbach, the brother of legendary Celtics coach Red Auerbach, designed the leprechaun logo associated with the franchise.
The logo has changed in color and detail over the decades. A full-color version appeared for the Celtics' 50th anniversary season in 1996–97, adding tan, gold, brown, and black to the earlier green, white, and black design. The cane remains one of Lucky's defining visual details.