A YJA Moment - Orcs

In the history of Earth, few creatures have generated so much fear as the species known as Orcs, Though not appearing physically opposing, Orcs were slightly faster, stronger, and more resilient than Humans,  They also possessed heightened, though their eyes had issues adjusting to sunlight.  The main advantage of the Orcs was their numbers - their masters were able to generate legions in a short period of time.

Born from the genetic code of captured Elven stock, the Fleshcrafters of Melkor the First Fallen engineered the perfect species to serve in the massive Army of Darkness.  These Orcs were birthed in vast underground labyrinths, born from artificial birthing pods. It is unclear how many were made in the First Age, but the ancient tome The Silmarillion hints it may have been in the millions.

The means to make Orcs continued into the Second and Third Ages, where they were the mainstay of the forces of Sauron, the Dark Lord who succeeded Melkor as leader of the Dark Armies of Mordor.  It would lend the knowledge to the Nephilim Wizard Saurman, who modified the Orcs in order to create his more capable Uruk-Hai.  The Uruks did not fear the sun's rays and were physically more imposing than their Orcish brethren, but took longer to gestate.

Despite a strong belief amongst the ancient humans to the contrary, Orcs were not intrinsically evil. Though they were birthed by foul magics, they possessed free will and a soul, granting them the ability to be noble if they decided to be.  However, the Orcs in the service to the Dark Lords were under a geasa of servitude, backed by an imposed culture of brutality that encouraged cruelty and viciousness over reason and compassion.

Orcs were a major presence in Middle-Earth until the end of the Third Age.  The final defeat of Sauron ended the Dark Kingdom of Mordor and sent the Orc tribes scattered across the continent.  The remains of the armies of  Rohan and Gondor, as well as the last few Elves and Dwarves pursued the Orcs and slaughtered as many as they could.  The rest presumably died out in the years of the Fourth Age before the founding of ancient Sumer.

Yet it's believed that like the Dwarves, there are birthing chambers full of Orcs far underground, awaiting the call of a new Dark Lord to awaken.