In the original Japanese version of Street Fighter II, the character called Balrog in the United States is named M. Bison. The name swap was part of Capcom’s overseas localization of the game.
The boxer was designed as a visual and thematic pastiche of Mike Tyson, and the Japanese name is commonly understood as “Mike Bison.” When Street Fighter II was prepared for international release, Capcom changed the names of three Shadaloo bosses. The boxer became Balrog, the claw-wielding Spanish fighter became Vega, and the final boss became M. Bison.
This creates one of the series’ most famous naming traps. In Japan, “Balrog” refers to the Spanish claw fighter, while “M. Bison” refers to the boxer. In the United States and much of the West, those identities are reversed. The change has been acknowledged in later Street Fighter material, but the Japanese-versus-international distinction remains the canonical explanation for the original games.