During Project-E, several dozen prototypes appear to have been built before a fully functional Evangelion was constructed. While most of these prototypes bears a striking resemblance to Evangelion Unit-00 above the neck with just a spine connected, the original prototype was different having five eyes suggesting there could have been even more variation than what was shown in the designs before they settled for the single eye.
The fact that the majority of failed prototypes resemble Unit-00 suggests that the iteration of the prototypes shown were the final as thats the design which carried forward to the first functional unit.
Using the knowledge and sample of Adam gained from the Second Impact, Gehirn set out to create their own powerful weapons which would be known as Evangelion under the name of Project-E. During this project, many prototypes were created with at least two different variants, potentially more until eventually, a functional unit, Evangelion Unit-00, was produced.
The failed prototype units were scrapped by 2005, ten years before the series begins. The remains of the failed Evangelion Prototypes were subsequently stored in the "Eva Graveyard" located in Terminal Dogma, which according to Ritsuko Akagi was nothing more than a dumping ground for the corpses. By 2015, most of the organic parts of the failed Evas have rotted away, leaving little more than an armored head connected to a spinal column, often accompanied by an incomplete set of malformed limb bones, hinting at their original, perhaps horribly deformed appearance. All of the failed Evas have orange-colored armor on their helmets, similar in design to Unit-00's original orange armor. The word "Reject" is printed on their heads in large red letters.
During the siege on NERV Headquarters, Misato drives past the graveyard in her car as she explains the true nature of the Angels and the Evangelion to Shinji. Over a dozen failed units can seen suspended vertically by their heads and display considerable variation in their face structure, some even looking like a human skull (showing the link between Evas and humans). Some also have labels on their spines identifying the vertebrae.
- During the shot of the Evangelion graveyard, at least 50 failed prototypes can be seen.
- The Director's Cut of Episode 23 depicted a markedly different graveyard. In the original version, the skeletons of the failed Evas were laid out on a massive empty floor in a single gigantic underground chamber, with what remained of their limbs carefully matched up with their heads and spines and surrounded by humanoid-shaped chalk outlines. In the Director's Cut, dozens of Eva corpses were simply haphazardly thrown into a pit shaped like the Tree of Sephiroth.