There's a great deal of material concerning alien reptilians on the internet. There were many attempts to trace their roots through the Summerian records of the Annunaki.
In early Christianity, there were the Gnostics' records and their insights into the dark forces called "The Archons"
In actual fact, the ancient repitilians were natural predators trained in hand to hand combat. Many a warrior, could single handedly take on a Tyrannosaurus Rex with just a sword and kill it.
About 65 million years ago, their pray (the dinosaurs) and food supply were wiped out, by humanoids (Atlantians?). This led to the reptilians becoming even more warlike. They conquered and stole technologies from many races. This included genetic engineering tech, mind control devices and holodeck tech.
Abductees and psychics have stated that the reptilians and greys feed off the fear and negative emotions of humans.
In the "Star Trek Voyager Holodeck Nazi Program" above, the plan would be to induce as much fear as possible in the victum before the kill.
Some people like David Icke are very paranoid of reptilians and seem to see them everywhere. Check out the subject on YouTube.
Not all the reptilians were enslavers, Enki, an ancient Summerian god tried to bring knowledge and freedom to mankind. Apparently, he lost his battle for control of Earth from his brother Enlil. In some places, Enlil is referred to as Yahweh.I don't believe that reptilians were shapeshifters (I may be wrong), but I do believe, they had thought amplifiers (like mental alternators) that could induce/create hypnotic suggestions or holograms at close range.
Human abductees' memories are/were valuable because they were short, with very intense emotions. For those who don't have much of a life like some ETs, these memories were probably like reality TV programs.
St Johns