Pa Bil Sag (or Pabilsag) was the tutelary god for the city of Isin in Mesopotamian mythology. He is connected to the lost city of Larak and was the consort of the goddess Nininsinna. Together they bore the god of rebirth Damu, according to some texts. One of the most important texts regarding Pa Bil Sag is about his journey to the city of Nippur where he honoured the god Enlil and presented him with many gifts. During this time, he was awarded the title "the wild bull with multicoloured legs".
"Origin: Iraq. A half-scorpion, half-human therianthrope. He is the Babylonian guardian of the gate connecting the human and demon worlds. Gilgamesh descended through this gate on his search for immortality. The Centaur of Greek lore is said to be modeled on Pabilsag."
"A half-man, half-beast monster from Mesopotamian mythology. He is also called Ninurta and revered as a god of war. Pa Bil Sag is both highly intelligent and tremendously strong. He resembles a cross between a man and a scorpion in appearance, and is said to guard the gate between the human world and the demon world. When the hero Gilgamesh descended into the demon world in search of immortality, he came to this gate guarded by Pa Bil Sag. Pa Bil Sag aimed his bow at Gilgamesh, and was such a terrible sight to behold that even Gilgamesh, slayer of countless monsters, recoiled in fear. Later, when Marduk achieved godhood and started a war, Pa Bil Sag fought alongside Tiamat, the goddess who gave birth to the gods, but was defeated. Pa Bil Sag is thought to be the model for the half-man, half-horse centaurs of Greek mythology, and for the modern constellation Sagittarius."
—Shin Megami Tensei IMAGINE Compendium
Pabilsag can be contracted within the Shinagawa Catacombs of the Templar Knights.
Pabilsag is the messenger of the God Enlil and the one who Flynn must deliver Heaven's Tablet to in the New Game Plus Challenge Quest, Retrieve the Tablet. He resides in a building found on Ginza - Shopping District in both the first playthrough and NG+. He states that the Tablet of Heaven's Will holds the destinies of the Gods, which is why they can not touch it themselves and must rely on Flynn to retrieve it. After obtaining the tablet he confesses that he had always viewed humans as weak, but realizes that might be an error considering he obtained such an important item. He leaves to take Heaven's Tablet to his father Enlil.