A total of 11 Titans are confirmed to exist in Godzilla: King of the Monsters, but never actually appear on-screen. Their names and locations are revealed via a monitor screen at one of Monarch's bases. By the end of the movie, the Titans have abandoned their resting places, but some have returned or have found new places to hibernate - and that same notion may apply to these 11 missing Titans.
Before King of the Monsters, Legendary's MonsterVerse had only two confirmed living Titans (Godzilla and Kong), and seven more were introduced over the course of the film. Three of these new MonsterVerse Titans - King Ghidorah, Rodan, and Mothra - are established monsters from Toho's library of kaiju. The rest, on the other hand, are original to the MonsterVerse. the third M.U.T.O. all make their big screen debuts as they break out of containment after being woken up by Ghidorah's call.
The four Titans Rodan at the end of the movie to bow down to their new alpha, Godzilla, who had just defeated King Ghidorah. As for the other 11 Titans in the MonsterVerse, they don't make it in time to witness Godzilla's victory, but though they never appear in the flesh, what their names mean to certain cultures can shed some light on what these mysterious creatures look like in the MonsterVerse.
Bunyip
Located at Monarch Outpost 99, at Ayers Rock in Australia, was Bunyip, a Titan whose name connects him to a creature from Australian Aboroginal mythology. To the people indigenous to this region in the 19th century, Bunyip was a black animal who may have like a seal and had a load roar that frightened the locals. There were numerous sightings of Bunyip, but descriptions weren't consistent. Said to have a long neck, Bunyip has been compared to a seal, hippopotamus, a manatee, and more. This doesn't provide a clear image of what the MonsterVerse's Bunyip looks like, but it's possible that he's a long-necked, hippopotamus, or seal-like creature native to Australia.
Abaddon
Being monitored in Wyoming was a Titan named Abaddon. Abaddon is a Biblical name from the New Testament's Book of Revelation. Described as the king of an army of locusts, Abaddon is referred to as the "angel of the bottomless pit", and the "Destroyer". He's even been called the Antichrist by some Biblical experts. So while there are no clues about what Abaddon actually is in the MonsterVerse, the fact that Monarch has given the Titan a name with such ominous meaning suggests that the creature may be one of the MonsterVerse's most malevolent and destructive Titans.
Mokele-Mbembe
Mokele-Mbembe, a Titan being held in Sudan, was shown on one of Monarch's screens for a brief instant, but his body was so obscured by smoke that it was impossible to make out any distinguishing features. However, the Godzilla: King of the Monsters novelization paints an incredibly clear picture of the monster. Mokele-Mbembe, who shares his name with a creature who was thought to have lived in the Congo, is an "earless elephant" with a mouth like a crocodile, over a thousand teeth, a curved horn on his head. In the book, he uses his long tail and trunk to escape from captivity.
Sekhmet
A Monarch outpost in Cairo, Egypt was responsible for watching over Godzilla vs. Mechagodzilla.
Leviathan
In the Bible, Leviathan is an enormous sea creature and the counterpart to the land-based beast, Behemoth (who also exists in the MonsterVerse). Leviathan is also the folklore legend, the Loch Ness Monster, which is made obvious by the fact Monarch was monitoring him at a base in Loch Ness, Scotland. In the novelization of King of the Monsters, it's said that Leviathan travels through the ocean through the Hollow Earth tunnels. One of the entry points is underneath Loch Ness.
Quetzalcoatl
Contained in Machu Pichu, Peru, was the Titan, Quetzalcoatl. To the Aztecs, Quetzalcoatl was a feathered serpent god. Typically, Quetzalcoatl is depicted as a green serpent-like monster covered up in colorful feathers. The Incas worshiped a similar creature, but theirs was called Amaru. The MonsterVerse could be linked to both creatures, since he shares his name with the Aztec god but resides in the Lost City of the Incas. It could be that the Aztecs (and the Incas) saw a giant serpent with feathers and that's what spawned the myths of Quetzalcoatl and Amaru.
Baphomet
The Titan known as Baphomet was kept at an outpost in Volubilus, Morocco prior to Ghidorah's wake-up call in Godzilla: King of the Monsters. The name "Baphomet" is tied to an idol head worshiped by of the Knights Templar. Historians have claimed that Baphomet was a twisted interpretation on the founder of Islam, Mohammad. This connection doesn't provide any insight into the Titan's identity, but his location could provide a clue. Volubilus is a city that was built 2,000 years ago. Walls found in the ruins of Volubilus include pictures of Acteon, a hero who turned into a stag. It may be that Baphomet resembles Acteon in one way or another. Since its hard to nail down exactly why Monarch gave this Titan the name "Baphomet", Baphomet's true nature will have to remain a mystery for now.
Typhon
Who is Cambodia's Titan, Typhon? In Greek mythology, Typhon was a giant snake monster with a hundred heads who engaged Zeus in an epic battle. According to the myths, Typhon was defeated by Zeus when he struck him with a thunderbolt. If the Titan of the same name is anything like the creature who fought Zeus, he could give the MonsterVerse another immensely powerful, multi-headed dragon.
Amhuluk
Though based in Russia, Amhuluk has the same name as a creature from Native American mythology. To the Kalapuya tribes from western Oregon, Amhuluk was a fearsome monster who lived near a lake and drowned anyone who came close. Stories of Amhuluk, a four-legged spotted sea serpent with horns, were told to keep children out of the water. It could be that this Amhuluk actually existed in the MonsterVerse, and that at some point in his lifetime he used the Hollow Earth tunnels to travel from Oregon to Russia.
Tiamat
In King of the Monsters, it's mentioned that a Titan in Stone Mountain, Georgia has escaped from his outpost. The Stone Mountain Titan is Tiamat. In ancient Babylon, Tiamat is regarded as the goddess of the ocean and a deity who helped create the Earth. Some have believed her to be a water dragon of some kind. Based on the name, it would seem that whatever the MonsterVerse's Tiamat is, it dwells primarily in the water.
Yamata no Orochi
Monarch was keeping track of a Titan who lived beneath Mount Fuji, Japan. This Titan is and perhaps even a direct relation -- to Ghidorah. In Japanese mythology, Yamata no Orochi was an eight-headed dragon with eight tails and red eyes. It was also the inspiration for King Ghidorah himself. Toho even made their own version of Yamata no Orochi and featured him in a few movies, including Orochi, the Eight-Headed Dragon.
