SPARTAN-117, also known as Master Chief, is a fictional character and the protagonist of the Halo video game series created by Bungie and developed by 343 Industries. He is a supersoldier belonging to the SPARTAN program, designed to enhance human abilities for combat. Clad in green armor, he is known for his exceptional skills in warfare and leadership. Throughout the series, SPARTAN-117 battles various alien species, including the Covenant and the Flood. His story explores themes of heroism, sacrifice, and the struggle against overwhelming odds. He is often accompanied by his AI companion, Cortana, who assists him in missions and provides critical information.