Titan (Volume 0)

Titans (巨人) are a race of giant man-eating humanoids that serve as catalysts for the events in Attack on Titan Volume 0.

Appearance
All Titans have a very similar appearance. They have humanoid bodies with a thin frame and lack external sexual organs. Their exact height is unknown, but they are big enough to hold an average human with one hand. They lack hair, pupils, and their teeth are exposed.

Creation
The Titans were part of a human extermination project led by scientists and religious groups 100 years before the story after a global crisis. These groups then began the "Mankind Destruction Operation," unleashing the Titans upon the world.