He studied at Benson Polytechnic High School in Portland, Oregon, where he was a star basketball player.

[1] After serving briefly in the U.S. Army, he was recruited in 1954 to the Harlem Globetrotters where he played for two years and toured with the team.

Hannibal's TV acting debut was in 1963 on "CBS Repertoire Workshop", where he narrated the story of the historical Dred Scott Supreme Court case.

[2] As a child, Hannibal was featured on the "Stars of Tomorrow" show in Portland.

He sang throughout the 1960s and early 1970s in various Portland venues including the Jazz Quarry and the Prima Donna.