It is said that Gregornous was once a magical entity and agent of the Wyld, but he doesn't remember his past life before he was invoked by Baba Yaga during her feud against the Nosferatu Antediluvian. Baba Yaga, having become a creature of darkness, turned the Great Zmei into her thralls as servants of the Wyrm
Of all the Great Zmei, Gregornous is the most eager to please the Hag. He believes he only exists to serve the Little Grandmother, and that this is also true to the other Zmei, even if they will not admit it. Therefore, it's only natural that he is inclined to show them how to properly respect their master. His hex scream makes plants wilt, the earth shake, buildings tumble and the life force of the world scream in pain.
Gregornous is roughly 50 feet long, his tail alone is 20 feet long and his scales are as black as soot. His presence causes despair in most who look upon him. His scales do not shine, and looking into his eyes is like staring into the void.
He was accidentally awakened in a battle between a Technomancer and a Celestial Chorus mage during World War II. The Paradox spirit unleashed during battle purged the area of magick that did not conform to the laws of science, including the binding spell that held the Great Zmei. Always clever, Gregornous laid low, hidding in the wilderness to figure out what was going on in the world since he fell asleep. During this time he secretly watched over Baba Yaga's resting place until she finally rose.