User blog comment:Kogath/Monster Hunter 4 Ultimate for the Nintendo 3DS/@comment-6050823-20150727143435/@comment-6050823-20150727193153

This slime mold is only found in the Lava Island or other special environments due to it needing very high temperatures and very high pressure, limiting the areas where it can be found and used by Brachydios(Basically I mean that Raging Brachydios, or in other words, strong Brachydios individuals are the only ones able use this special slime mold without being killed by it). Due to the Lava Island's harsh environment, long dormant slime molds in this area can become active again after something as simple as crustal deformation or eruptions in the area. From being long dormant, these slime molds have accumulated large amounts of power and have much more explosive power. So yeah, most likely a new yet similar slime mold or just a special form of the slime mold we've seen previously due to the environment having harsher conditions.