Unidentified dinosaur-like Titan

The Anguirus アンギラス (Angirasu) of the MonsterVerse is a mutated Ankylosaurus created by Legendary Pictures that appears in Legendary's 2019 film Godzilla: King of the Monsters as a skeleton next to an entrance to Hollow Earth

Name
The original English name given to Anguirus by Toho was "Angilas", given the pronunciation of the name in Japan, which was changed to Anguirus in the 1959 American release of Godzilla Raids Again, with the film's title being changed to Gigantis, the Fire Monster. In the mid-1990s, Toho copyrighted the revised name "Anguirus," making it official. This name has been kept the same for the MonsterVerse.

Appearance
Anguirus is a four-legged dinosaur-like creature that combines the features of an Ankylosaurus, a Styracosaurus, and a crocodile. He has several horns at the top of his head and a single rhino-like horn above his nose. In death, all that remains of Anguirus is his skeleton.

Godzilla: King of the Monsters
At some point, Anguirus fought and was killed by another Titan near an entrance to the Hollow Earth cavern constructed by ancient humans for Godzilla, possibly after a failed attempt to get inside. Monarch would later briefly pass Anguirus' skeleton as they followed Godzilla into the cavern, millennia later.

It is possible that there are surviving members of Anguirus' species that may be known or unknown to Monarch.

Films

 * Godzilla: King of the Monsters (as a skeleton)