- Order: Caudata
- Suborder: Demon Frog
- Family: Cabra
Within the Old World, Berserk Tetsucabra inhabit the Sunken Hollow, when the volcano is dormant in the area, and the Volcanic Hollow, when the volcano is active. Berserk Tetsucabra can also be found rarely in the Everwood.
Berserk Tetsucabra prey upon anything smaller than themselves that ventures too close to the water. This includes Kelbi, Aptonoth, Jaggi, Rhenoplos, Gargwa and Slagtoth. Due to their large size and tough armor, they have only other large predators to be wary of. These include Nerscylla, Deviljho, Najarala, Glavenus, Stygian Zinogre, Agnaktor and Teostra.
From Berserk Tetsucabra's habit of using explosive rocks, its scales have become dirty from the soot and gases from the explosive rocks it uses. This has also changed the color of its face, which changes color after each rock that explodes near its face. If looked at closely, some of its original colors can still be seen. Despite its body becoming dirty, the soot and gases have actually made the Berserk Tetsucabra's scales, jaws, and shell tougher, making it resistant against to the explosions of the rocks. Berserk Tetsucabra tusk are heated like iron.
Berserk Tetsucabra are a lot more wild and aggressive than Tetsucabra. From the fact it uses explosive rocks for defense is one of the reasons why the Guild consider them berserk or wild compared to Tetsucabra. Its unknown if the Berserk Tetsucabra have the same breeding habits as the Tetsucabra.