Abaddon

Abaddon, also dubbed Titanus Abaddon, is a prehistoric giant created by Legendary Pictures that appears in Legendary's 2019 film, Godzilla: King of the Monsters, as a name briefly seen on a monitor.

Name
"Abaddon" is a Biblical Fallen Angel, sometimes the Angel of Death and sometimes the Angel of Destruction. He is notably mentioned to have had an army of locusts. It is unknown whether Titanus Abaddon has any connection to the angel, or whether it's just a codename designated by Monarch for an unknown reason.

Godzilla: King of the Monsters
At some point, Abaddon had a Monarch Outpost built around him. When Ghidorah calls all the Titans, Abaddon breaks free and begins to hunt with his new pack. When the ORCA calls all Titans to Boston, Abaddon does not arrive in time to see Godzilla become the new alpha of all Titans (except Kong).

List of appearances

 * Godzilla: King of the Monsters