Dagon

Dagon is a demon in Amazon series Good Omens, also known as the Lord of the Files.

Background
Dagon was once an Angel, who decided to take part in Lucifer's revolution, and was cast to Hell alongside 10 million other Angels, who then became the Demons.

In Hell, Dagon became known as the "Lord of the Files" and "Master of Torments". It is possible that Dagon influenced humanity over its history to create the ancient Mesopotamian and Canaanite Deity of the same name and the Great Old One from the Cthulhu-mythos.

Significance in Series
Dagon was contacted by Crowley around the 11th Birthday of both Adam Young and Warlock Dowling, asking about the Hellhound that was sent to meet the Antichrist. He confirmed that the Hellhound was set loose.

Dagon was later seen alongside Beelzebub, holding a motivational speech to all other demons, describing how they are "tougher, smarter and more dangerous" that the angels of Heaven.

After Crowley and Aziraphale stopped Armageddon, Dagon was sent to collect Crowley, alongside Hastur and one other demon. They captured and brought Crowley back to Hell.

At Crowley's trial, Beelzebub and Hastur served as the Judge and prosecutor, respectively. When Crowley asked if Dagon would represent him, Dagon stated that they were just there in case "there's anything [Crowley had] done that they forgot".

Personality
Like most demons, Dagon appears sadistic and enjoys tormenting people and other demons, taking his job seriously.

Dagon notably viewed Lucifer's rebellion against God as a "glorious revolution", while most others, real or fictional, view it as a prideful betrayal against the Almighty.

Quotes

 * "Cooperation with our old enemies."


 * "Right. Listen up. Any moment now, we'll be leaving Hell and we'll be going up against the army of angels. Now all of you were angels once, and we fought in the glorious revolution. And we lost! But that was then. We have had thousands of years to get tougher. Smarter. And more dangerous! I want you to repeat after me! Tougher! Smarter! And m--"


 * "Oh I'm afraid not. No I'm just here in case there's anything you've done that they forgot."

Notes and trivia

 * Dagon is the name of a deity in the Cthulhu Mythos, and before that a Mesopotamian fertility god.
 * Dagon's title "Lord of the Files" is a comedic spin on Beelzebub's title "Lord of the Flies".
 * Dagon is also the Master of Torments
 * Dagon uses he/him pronouns (as noted in the Good Omens script book)