| Azarrath | Fiend | - | Balor lieutenant of Graz'zat, master of Thanatos | ||||
| Bel | Fiend | - | Pit Fiend Lord of Avernus, the First plane of the Nine Hells | ||||
| Bramandin | Fiend | 1601 | Mortal Hunter assassin hired to kill Varkar's slayers, killed by them | ||||
| Cambion | Fiend | - | A cross-breed between a devil or demon and another sentient race, usually a human. Also called a half-fiend. | ||||
| Demogorgon | Fiend | - | The dual-lived, dual-willed prince of the Abyss, master of the mysterious and king of the deviants. | ||||
| Demon | Fiend | - | The chaotic fiends inhabiting the Abyss. They are ferocity personified and will attack any creature just for the sheer fun of it—even other demons. | ||||
| Graz'zat | Fiend | - | The Dark Prince, a demon lord equal to Demogorgon and Orcus | ||||
| Idalla | Fiend | 1600 | Succubus trapped in Khundrukar since its' fall, slain (on the Prime Material) by the party | ||||
| Orcus | Fiend | - | Lord of the Undead, Demon Prince and Lord of Thanatos | ||||
| Orcus, the Cult Of | Fiend | - | Followers and worshipers of Orcus | ||||
| Saethor | Fiend | 1608 | Use-name of the Nightmare Yeluzal | ||||
| Seraphiel | Fiend | - | The Dark Angel, Orcus' prime battle commander | ||||
| Tiefling | Fiend | - | One descended from a cambion ancestor, but of less than half fiendish blood. | ||||
| Tubalcain | Fiend | 1655 | Imp working for Iboleth, staff wizard to Bardrum governor of Lossal | ||||
| Yeluzal | Fiend | 1608 | True-name of the Nightmare Saethor | ||||
| Yugoloth | Fiend | - | Non-aligned and mercenary fiends, neither demon nor devil | ||||
| Zabryat | Fiend | - | Marilith general serving Orcus, worked with Surya in the freeing of Orcus but betrayed by him on Thanatos | ||||
| Zoravam-Anasvish | Fiend | c.-5000 | Female General in the armies of the Abyss, fought in the Blood War |