Lavacrest is a city of monsters built deep within the Nether. It is hidden deep within a large formation of netherrack, protected by many spells. Monsters of all kinds can be found there, including those natives to other Dimensions such as the End or Overworld.
The monsters of Lavacrest tend to be more honorable in the eyes of Aetherians and Terrarians, although they are a nightmare to the forces of Herobrine. Monsters use their abilities for their quest against Herobrine, and tend to assist Aetherians and Terrarians in trade or combat.
They are much more intelligent and powerful than their brethren which plague the surrounding Nether, Overworld, End, and whichever dimension they hail from. They display a form of benevolence, treating Rarg fairly even though he is an agent of Enderstar while also protecting Eeebs while allowing Tufty and Meowz to study there.
Monsters who live in Lavacrest have a greater amount of intelligence than their brethren who serve Herobrine. The sorcerer Grayfellow teaches the monsters magic. Many of their magical feats include making buildings ungriefable, and creating booby traps. They have enchanted Eeebs to be much stronger than a normal kitten using a Rune Chamber. Also they have many unknown abilities and do not burn in daylight.