The mythical giant-king Ettin is a villainous figure from Diounic mythology, often equated to the goblyn divh Jarvish by the landsmen of Ahlonia. In the Book of Ahlana Ettin is the ruler of Ahlonia, reigning over the Terenshee and goblyns of the land, and leading the fearsome giants. In those days such creatures walked in the open, with no fear, and Ettin sat in a throne carved from a mountain that pierced the clouds. When the Dioune came to Ahlonia they saw these evil creatures cavorting, and Koroth fought Ettin in single combat, slaying him and then skinning him and wearing his hide. Legends of the battle vary, but most say that Ettin had to be blinded, either because he could see into the future, and thus avoid every one of Koroth's blows, or because his skin was harder than steel and his eye was his only weakness. Some legends hold that Aliel blinded Ettin with a bright light, others say that Koroth simply drove the killing blow from his spear through the creature's eye. When the Dioune ascended into the sky the terenshee and goblyns were so afraid that they fled into the cover of the dense forests and under the ground respectively to hide from the gaze of the avenging Koroth.

Ettin was described and later depicted as a monstrously fat, hairy creature with no discernible neck and a single eye in the center of his forehead. Some texts say that his eye allowed him to see the future, and Koroth had to first blind Ettin before he could land a blow on the creature, however this may have been confused with a mythical artifact called the 'Eye of Ettin' said to have a similar power, but related to the mythical giant in name only. Koroth is said to wear armour crafted from the tanned hide of Ettin, and that it is impenetrable to worldly weapons.