She is a dragon, one of the five children of the World Serpent, according to the Wizardry Archives Manual. She is dedicated to the balance of the world, and she lives in her mountain lair. A long time ago she took the Orb of Earithin, as she thought it to be too dangerous in the hands of mortals.
When the heroes of Wizardry III: Legacy of Llylgamyn set out to look for her and the Orb of Earithin they will find out that L'kbreth is truly favouring the balance between good and evil.
The Ultimate Wizardry Archives (Manual), p. 63.