User blog comment:MeDeoPal/On the Origin of Titans and Shifters/@comment-67.81.50.105-20151113020501

The Titans were created by a scientist. Religious people didn't want him to conduct experiments for religious reasons. He ignored them, and kept conducting experiments. The people were angry, and burned his house down, killing his family. The people took the man into custody forbidding him to do science. Using his knowledge, he put some kind of bacteria or poison into the people's drinking water and such, turning them into the first Titans. The scientist was very mad at the world. He created the Titans so that they didn't require food or water. They made it so the Titans would eat humans for only pleasure. The scientist gave himself an injection, so that he could be a human and a Titan as Eren could. Erens father was a follower of this scientist, and have Eren the same injection. All of this information is from the manga. Just keep reading