Laurentius of the Great Swamp: A student of the pyromancer: Salaman, Laurentius was banished from his native home due to his curse of undeath. After being rescued in the Depths, he relocates to Firelink Shrine and teaches pyromancy. If the player joins the Chaos Servant Covenant, he will be impressed with your new pyromancy and ask where you obtained it. If told, he will try to visit the Fair Lady to learn the same pyromancy, but hollows in the swamps of Blighttown.
Chaos Witch Quelaag: She is a daughter of the Witch of Izalith, and along with most of her family failed to escape and was corrupted by the chaotic flame. Quelaag and her sister became spider-like creatures with their original torsos extending from the monsters' backs, and made their home in Quelaag's Domain near Blighttown. She attacks any undead entering her realm to collect humanity for her ailing sister.
Manus, Father of the Abyss: The people of Oolacile were fooled by a serpent, resulting in the upturning of Manus's grave and inciting his wrath. He is the cause of the Abyss, which threatened to swallow all of Oolacile. Manus was once human and became the Father of the Abyss after his humanity went wild, eternally seeking his precious Broken Pendant. He's described as being primordial man, suggesting that he may be the Furtive Pygmy (not confirmed).
The Fair Lady: Quelaag's Sister was a Daughter of Chaos before the disaster that befell Izalith. While most of her sisters were transformed into horrible demons, she and Quelaag were able to escape with their sanity intact, although they were bound to giant spiders in the process. Quelaag and her sister took an entourage of servants with them, who suffered from a form of disease. Out of pity, she sucked out their pus against Quelaag's orders, weakening and blinding her in the process