Ahannu

The Ahannu, sometimes called the An, are a formerly spacefaring race of reptilian aliens that colonized Earth around 10,000 BCE and enslaved much of the human population. After their near-annihilation by the Xul, they regressed to a primitive state on Ishtar, though they retained some of their slaves and technology.

Anatomy
Ahannu are humanoid in general shape, but the resemblance ends there. They have reptilian features, such as scaly green skin, claws, and sharp teeth. Their eyes are extremely large for their body size, each about the size of a pear, and have long, horizontal pupils. The nose is flattened and the ears are completely internal. Ahannu are generally a little smaller than humans, about 1.5 m tall, but the "troll" variant reaches heights well in excess of 2 m, and possibly up to 3 m. Ahannu have six fingers on each hand and six toes on each foot.

Diet
Ahannu are omnivores, eating both plants and meat. Their biology uses right-handed amino acids and right-handed sugars, allowing them to gain nutrition from Earth organisms without issues.

Reproduction
Ahannu have three sexes: male, female, and drone. The drones are "neuter" Ahannu, and their function in the Ahannu life cycle is unknown.

History
The Ahannu evolved on a planet orbiting an unknown star, but presumably in the general area of Sol and Lalande 21185. They eventually developed spacefaring technology and spread from their homeworld. They reached Ishtar at an unknown point in the distant past, and established a colony there.

Ahannu colonists arrived on Earth around 10,000 BCE. They conquered and enslaved humans, who they called "Blackheads" due to their hair, in various regions of the world, but especially the Middle East. Humans called their masters the "An" and developed religions venerating the Ahannu as gods. The Ahannu took thousands of humans back to their other colonies, sometimes as slaves and sometimes as food.

In about 8,000 BCE, the Xul discovered the Ahannu and attacked them. They bombarded the Ahannu colony worlds and their homeworld with asteroids, destroying the majority of the species. The Xul wiped out the Ahannu on Earth with an asteroid aimed at the Arabian Sea, causing catastrophic floods that laid waste to the region and gave rise to the concept of the Great Flood. However, the Xul overlooked Ishtar due to its location outside its star's habitable zone, allowing its population to survive in a greatly reduced state.

Technology
The Ahannu formerly possessed advanced technology, but after the Xul genocide they regressed severely. Ahannu weaponry consists primarily of bladed weapons, although they do still retain some handheld coilguns. They are also capable of genetic engineering to some degree, as shown by the creation of the "mountain-great-warriors," known to humans as trolls. Prior to their fall, they used antimatter as fuel for spacecraft, and even afterward used it to power some advanced weapons. Uniquely, they developed a biological computer system allowing the sharing of consciousness and memory, and used it to retain knowledge of their former technology and to coordinate military tactics.