Malkariss was an extremely arrogant and deformed white polecat. He founded an underground kingdom beneath the ruins of Loamhedge Abbey in the far south, built by slaves delivered to him by slavers such as Slagar the Cruel. He was represented by a large limestone statue of a polecat which was in a room full of crystals. He used a basket connected by a rope to the statue to transport himself. He spoke only to his head rat Nadaz to relate his orders to others under his rule.
After Matthias fell off the ledge where the statue dwelt during his fight with the Wearet, he discovered Malkariss in his true form: a white polecat, but not at all like the imposing statue. In reality, Malkariss was old, weak, and hideous. Malkariss tried to kill Matthias with his own sword, but a small group of the slaves, whose guards had left them alone when they left to go fight the intruders, threw rocks at him, killing him. The limestone statue was the symbol of the slaves misery, so it was destroyed by Orlando the Axe and Matthias. After it fell off the nearby edge, it caused an earthquake. This earthquake caused Matthias and Orlando the Axe to be shot upward from the ground like a geyser, where they landed in a tree.