Abaddon

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

Godzilla: King of the Monsters
At some point before 2019, Monarch established an outpost around Abaddon in Devils Tower, Wyoming. When Ghidorah calls all the Titans, Abaddon breaks free and begins to hunt with its new pack. When the ORCA calls all Titans to Boston, Abaddon does not arrive in time for the battle and does not see Godzilla become the new alpha of all Titans (except Kong).