Here’s my take on a Girtablilu (or Aqrabuamelu, or simply Scorpion-man), a category of monster with an ambiguous nature, from Mesopotamian mythology. As one of their names indicates, they generally resembled half-man, half-scorpion hybrids, although some representations also adorned them with bird feet, or even wings. They are among the creatures that the primordial goddess Tiamat engendered to fight the younger deities responsible for the death of her mate Apsu. However, they seem to have pledged allegiance to their adversaries following the defeat of their mother, but we will come back to that.
According to the Epic of Creation (or Enuma Elish) written during the 12th century BC, while the primordial couple formed by Tiamat (personifying salt water) and Apsu (personifying fresh underground water) shared a still chaotic Earth with the young gods it had engendered, tensions eventually arose. Apsu, exasperated by the activity of his descendants, decided to exterminate them. Although she disapproved, his terrible companion did not prevent him. But her spouse was defeated by Enki, the cunning god of craft and arts, who then became the master of fresh underground water in place of his ancestor. Furious, Tiamat prepared her revenge, and began to give birth to eleven monsters as fearsome as they were hideous, including the Girtablilu. Not only were they gigantic to the point of reaching the clouds, and were armed with darts capable of killing a human in a handful of seconds, but they were also perfect archers who never missed their target. The formidable hybrids put the young gods in great difficulty, until Enki sent his son Marduk, the god of thunder, into battle. He triumphed over the monstrous army and defeated Tiamat, whose corpse allowed the Earth as we know it to form.
As for the fate of the Girtablilu – it is not excluded that there might have been only one specimen in this context, by the way –, it remains mysterious. Were they exterminated or spared, it is not clarified.
In the Epic of Gilgamesh, supposedly written between the 18th and 17th centuries BC, that is to say before the Enuma Elish, but taking place at a time after the creation of the world, the eponymous hero meets male and female Girtablilu. Following the tragic death of his only friend, the wild man Enkidu, King Gilgamesh became aware of the fragility of life, and set out to find Uta-napishti, a survivor of the Flood who had become immortal, in order to learn his secrets. His wanderings in the desert expanses beyond his kingdom led him to the Twin Mountains, the true border between the world of the living and the underworld. The said mountains were guarded by an imprecise number of Girtablilu, charged with opening and closing the rocks each time Shamash, the sun god, passed by, leaving the world of darkness at dawn, and returning there at dusk. Upon seeing the hybrid monsters, Gilgamesh was struck with terror, not unaware of their ability to kill with their gaze (a power that is not mentioned in the Enuma Elish, and which they can choose not to use), and hid his face. However, a male Girtablilu sensed that the king had divine flesh in him, being a demigod, and his female, with superior acuity, perceived that only a third of his being was human, against two divine thirds. The couple of giants then showed no hostility, inquired about the purpose of his journey, and warned him that no mortal had ever returned from the other side of the Twin Mountains. But Gilgamesh was determined, and the Girtablilu informed him that he would have to travel 120 kilometers in total darkness before reaching the end of the world, and the immortal Uta-napishti. Then, they left the king to continue his mystical journey, closing the mountains behind him.
Thus, over the centuries that separated the writing of the Epic of Gilgamesh and that of the Epic of Creation, the perception and role of the Girtablilu have changed drastically, and to seek a real link of continuity there would be over-interpretation. Nevertheless, one could imagine that, following the defeat of Tiamat, the Girtablilu could have been spared by the young gods (including Shamash), by agreeing to fulfill this role of guardians of the Twin Mountains.