The Kroblins of the western mountains

The Ukari of Mt Vulmar are the dominating race of Zurrican. They are a passive and peaceful people for the most part only engaging in acts of war when pressured or pushed into conflict never seeking out conquest or bloodshed.
That same way of life can not be said for the bloodthirsty and ruthless Kroblins of the mountains on the western reaches of Zurrican. This large and fairly unintelligent race has over the years been unable to process or create much around them but rather stealing, murdering and plundering most of the items that they posses. Isolated from the rest of the world and unwilling to create alliances the Kroblins are a culture that stands out from the rest.
They do not conduct in trade and they do not take kindly to visitors or travelers in their lands.
Their mountain fortress is invisible to the naked eye as the opening and entrances are hidden in the rock and ground.
They also do not posses the ability to read or write and only have the means of communicating with one another through grunts or growls. They have never allowed another race to enter their lands making it near impossible for them to understand the languages of the surrounding countries and kingdoms. Many have attempted to root these vile pillaging miscreants from their mountain lair with absolutely no success.
The Kroblins are not a small race and have been easily able to outmatch any who come into their territory. With all of the stone and ground openings that are hidden making them near impossible to find if they don't want to be found.
With the lack of intelligence they have been unable and unwilling to set forth and conquer the land around them their strength comes from the mountain and to be caught in the open would almost certainly lead to death.