"Although most of the crystals deposited on Earth by the meteor showers (sent by SpaceGodzilla in order to escape from his prison in Godzilla: Save the Earth) embedded themselves in the surface, some of them managed to punch through the earth's crust and enter the lithosphere. There, brought together by the magma flows from within the earth, a sentient creature was brought to life by the accumulated power of the crystals and the raw, ferrous materials of the earth. Obsidius emerged from a volcano onto the surface world only recently in conjunction with fellow mutant Krystalak, and thus far has resisted all attempts at communication. His virtually impenetrable mineral exterior shields him against both physical and energy assaults. He advances single-mindedly toward the most unstable crystal formations on the surface, and as such should be considered extremely dangerous."
Development
According to Art Director Robert Caracol, "Magmouth (an early, working name for Obsidius) was a combination of two separate concepts. The first was a rocky, craggy creature that was basically solid rock. The second was more akin to flowing magma. In the end, we came up with a blending of the two ideas, arriving at a monster that was a walking volcano. It possessed the hardness and sharpness of solid granite but could also attack using the molten fluid from within its body. One aspect that arose from this design angle was that it would possibly have to eat rock and debris to replenish its reservoir of magma after throwing it up in an attack". Obsidius managed beat Lightning Bug, The Visitor and Fire Lion and get into the game along with Krystalak.
Abilities
Obsidius is made of volcanic rock, therefore resisting most attacks on him. He is immune to lava, and therefore can run around in the lava pool on the Seattle arena in the game. He can curl himself into a ball and roll around at a higher speed. Many of Obsidius's attacks are similar to a gorilla, with his huge arms and and flexible legs playing a huge role in his attacks. Obsidius also has the ability to spit out burning lava (this attack is known as "Inferno") and burrow underground.
Criticisms
The original monsters were under heavy debate by fans of the Godzilla community. Many fans felt that they took up time and space that could be used to create other Toho characters instead. Fans who supported the original monsters said that every Godzilla monster was at one point original, and that the Godzilla Universe wouldn't hurt from the new additions. Atari and Pipeworks were quick in response, with Keehwan Her stating that the original monsters did NOT replace any classic Toho creations, and that plenty of classical Toho monsters would make the final cut.
Obsidius and Krystalak's roars are preformed by an uncredited Frank Welker, who has also had a large number of voice acting roles outside the Godzilla universe.
Obsidius is one of the few monsters who don't have eyes.
Obsidius's name was chosen by fans in an IGN poll after he was voted into the game. Other names that fans could have chosen include Pyrodorah, Kazango, Dotoryo, and Volcanis[1].
