Powers

As well as using teeth and claws to fight, Titanosaurus uses his tail as a weapon. By raising the sail-like fin and wagging it, he can cause winds strong enough to rip apart buildings and send the debris flying. If instead used in water, he can give form to whirlpools powerful enough to completely immobilize submarines

Films

Terror of Mechagodzilla (1975), Godzilla vs. MechaGodzilla

Origins

The Titanosaurus character has not appeared in any films since, aside from a brief flashback during the opening credits of 2004's Godzilla: Final Wars.

An amphibious dinosaur found in the Pacific Ocean, the character appeared only once, as one of two antagonists in the film. Titanosaurus shares its name with a real dinosaur species, though they do not share much beyond nomenclature; the real Titanosaur was a peaceful, land-dwelling sauropod, while the one featured in Mechagodzilla is a frightening, intense creature who sports a fin on his head and neck and one along his back, similar to Spinosaurus.

Originally, Titanosaurus was going to be two separate monsters that would eventually form into one, but due to budget restraints, only one.

In Terror of Mechagodzilla, a mad scientist named Shinji Mafune (portrayed by Akihiko Hirata) becomes so obsessed with studying the brain patterns of marine life that he loses his academic credentials and is cast out from the scientific community. Quickly, descending into madness, Mafune is able to gain control of Titanosaurus, with the help of  his daughter-turned-cyborg Katsura and aliens from Black Hole Planet 3, after it attacks a submarine investigating the remains of the destroyed Mechagodzilla, from the previous film, Godzilla vs. Mechagodzilla. Dr. Mafune rebuilds Mechagodzilla, and with both monsters under control, try to destroy Tokyo and create the first city of the new world. Both are ultimately defeated by Godzilla.