Beelzebub

Beelzebub is a character in Amazon series Good Omens and the leader of the forces of Hell and the archangel Gabriel's equivalent.

"In the Beginning"
When Crowley goes down to Hell to give an update on Warlock Dowling, the supposed Antichrist, Beelzebub asks if Crowley has encountered any problems from "the Opposition", but Crowley reassures that they don't suspect a thing.

"The Doomsday Option"
Crowley gives Beelzebub his presentation on changing the M25's shape into the sigil Odegra, which means "Hail the great beast, devourer of worlds" in the Dark Priesthood of Ancient Mu.

"The Very Last Day of the Rest of Their Lives"
Beelzebub serves as the judge at Crowley's trial, which ultimately ends with Crowley's (failed) execution. Later, Beelzebub stands beside Dagon as ze rallies the demons to fight against the army of angels. Beelzebub interrupts Dagon's rally because Beelzebub can sense that something is wrong.

Beelzebub then rises from Hell (as Gabriel descends from Heaven) to try to convince Adam Young, the actual Antichrist, to end the world and start the war between Heaven and Hell by telling him when the war is over he will rule the world. When Adam says he will not start the war, Beelzebub is startled and says ze must go back down to Hell to seek further advice. Along with Gabriel, Beelzebub vanishes. Later, Beelzebub is present at Crowley's trial.

Personality
Beelzebub is seen to be rather cold and calm, and is always frowning. The only time in which Beelzebub is seen smiling is when ze is trying to appeal to Adam to start the war, telling him that once the war is concluded, he will get to rule the world. Beelzebub is rather serious about the war between Heaven and Hell, becoming rather frustrated when Adam won't start the war and end the world.

Quotes

 * "When all of this is over, you're going to get to rule the world. Don't you want to rule the world?" - "The Very Last Day of the Rest of Their Lives"

Notes and trivia

 * According to Neil Gaiman, Beelzebub's pronouns are ze/zem/zir. This is likely a reference to the sound of a fly buzzing.