Titans

Titans are a race of giant, man-eating humanoids that serve as the antagonists of Shingeki no KyoGem. The people of Paradis were taught that Titans appeared over 100 years before the Fall of Wall Maria (850) and drove humanity to near extinction; all that is left of humanity is what's behind the walls, and the rest of the world was overrun by Titans. In reality, they are the transformed descendants of Ymir.