In Game Description
Brachydios is a member of the Brute Wyvern group of monsters. Included in this group are the Uragaan and Deviljho, among others. It is unique in this class because it has highly developed forearms, unlike the nearly useless forearms of most other Brute Wyverns. Underneath their forearms, Brachydios have two claws that could be used for grappling, struggling with prey and enemies, or possibly mating. The one defining aspect of Brachydios are their symbiotic relationships with an explosive slime mold that currently no other known creature used (Until the 4th generation.) Over time, Brachydios and their bodies have become highly resistant to heat. This is due to them living in the Volcanic region. The heat resistance of the Brachydios's Obsidian covered skin is demonstratedby how Brachydios are capable of withstanding an Agnaktor's heat beam. Contrary to most large predators, which tend to specialize in one specific environment, it seems that the Brachydios and its slime-mold are also capable of withstanding and thriving in frigid cold, as is evident by the presence of this monster in the Tundra region. With their highly developed arms, large head horn, and explosive slime mold, Brachydios are currently the most unique of their class.
Brachydios are extremely versatile as they have been found inhabiting both the blistering heat of the Volcano (3rd) and Underground Volcano,the freezing cold of the Tundra, and the temperate climate of the Deserted Island. In all three of these environments, it is easily able to insert itself as an apex predator, preying on local herbivores and possibly carnivores. A Brachydios's skin is very similar to a thermos flask, giving it the ability to withstand both extreme temperatures of hot and cold.
Brachydios is an apex predator, as is shown when it easily defeats an Agnaktor in its ecology video. It is likely that Brachydios competes with Agnaktor, Rathalos, Tigrex Subspecies, Tetsukabura, Teostra, and Deviljho in Volcanic areas; Barioth, Tigrex, Gigginox, Baleful Gigginox, Glacial Agnaktor in the Tundra; Lagiacrus, its Subspecies, Green Nargacuga, Royal Ludroth, Plesioth, Rathian, and Zinogre in the Deserted Island; and also competes with Stygian Zinogre both in the Tundra and Volcano. Brachydios will also prey on smaller predators such as Great Wroggi, Great Baggi, and Great Jaggi. With the unique slime mold at its disposal and its extreme aggression towards intruding monsters and hunters, it would be more than a match for most other predators. Elder Dragons like Alatreon ,Crimson Fatalis and Dire Miralis, along with the Flying Wyvern Akantor could be a huge threat to Brachydios because all of them are extremely dangerous, so the Brute Wyvern would prefer to stay away from them at all times.
The symbiotic slime-mold is easily one of the most unique and defining feature of the Brachydios. The theropod's armored shell is hardened to protect against the explosive blasts that the mold creates on impact. Brachydios' body is the only place this mold can survive without turning explosive. When attacking, Brachydios constantly scrapes copious amounts of this mold off of its body, causing it to deplete. However, it seems that the beast's saliva acts as a powerful stimulant, which causes the mold to almost instantly replenish itself. The mold seems to have chemical reaction when enraged, as even areas of this brute wyvern's body with a very fine and otherwise invisible coating of it flare up bright yellow. In this state, the mold becomes far more volitile and expodes when it impacts virtually anything. The method in which this slime mold congregates on young Brachydios has not yet been determined, but it is generaly believed that its explosions release countless spores that are sent long distances due to the blast. These blasts, combined with the very wide range of habitats in which the Brachydios is found, allows this mold to spread over great distances. Some scholars even believe that the mold may be able to grow in other environments, but that the shell of the Brachydios is the catalyst that makes it volitile. This theory has yet to be proven. In the New World, Brachydios have learned to use their horns to make a massive slime puddle that can kill prey and any other monster that doesn't have protection against it.
By using different shell fragments of a Brachydios, and a suitable specimine of mold, it is possible to culture this slime for weapons. However, the lack of saliva means that it tends to be less volitile and will only explode when a large amount has congregated onto something other than the host shell. Interestingly, slime molds for each Brachydios are different from the others, similar to that of fingerprints. Whenever the slime mold explodes, it will spread spores that will create more of the slime mold in a particular area or environment.
Brachydios are extremely aggressive creatures and will not hesitate to attack if they feel threatened or challenged. Due to their aggression they are commonly known to invade the territories of other large predators, usurp them, and claim the territory as their own. When young Brachydios will live near their parents and their territory, yet the adults will not show any parental care. The hatchlings will also pick up slime mold left behind by adults but this can be dangerous as their hides are underdeveloped and can possibly be seriously injured or even killed by the explosions of the slime mold. Some large individual Brachydios are known to go on rampages in areas such as the Tundra and Deserted Island's moga woods. The cause of these aggessive attacks is currently unknown.