Titans (巨人 Kyojin?, lit. "Giant") are the primary antagonists and the primary catalyst in the events of the Attack on Titan series. They are a mysterious race of giant humanoids that appeared roughly 107 years ago and rapidly exterminated humanity to the point of near-extinction. If put into a calculable perspective, the Titans first appeared in year 743. Their origins, overall numbers, and their physiological workings remain a mystery to humanity at this point in the story.