Who is the final boss in the original Street Fighter II?

The final boss in the original Street Fighter II is M. Bison. He is the last computer-controlled opponent in Street Fighter II: The World Warrior, appearing after the player defeats the four boss characters Balrog, Vega, Sagat, and then faces Bison.

M. Bison leads the criminal organization Shadaloo and uses a supernatural force called Psycho Power. In the original arcade game, he is not selectable; he became playable in Street Fighter II: Champion Edition and later releases. His aggressive charge attacks, Psycho Crusher, and rapid movement made him a notably difficult end-of-game challenge.

The name can cause confusion because Capcom changed the names of three boss characters for international releases. In Japan, the character known internationally as M. Bison was called Vega. The boxer was called M. Bison in Japan, while the Spanish claw fighter was called Balrog. Akuma became an alternate boss only in later versions, not in the original World Warrior release.