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.

Behavior
Their sole purpose in life is to seek out and devour humans.

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.

Physiology
Titans were said to be vastly superior to any living being. Not only did they have the ability of regeneration and semi-immortality, they were also able to shape-shift into the forms of humans. Their weak spot was located in a place inside their bodies which varied from Titan to Titan. This weak spot, called the "nucleus," had the form of a sphere surrounded by little spikes. Attacking this weak point is fatal. 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. People who can turn into Titans were also present, and were shown to have already infiltrated the military. Somewhat similarly to their current counterparts, killing them was impossible while they were in their human form, and attempting this would trigger their transformation. Only hitting their weak spots in Titan form would cause their death.

However, unlike current Titans, they do not need to eat a human with the power of the Titans to turn back into a human: They seem to be able to take the form of any human they eat.