Fiend, undead, and monstrous antagonists: devils, demons, the risen dead, and aberrant creatures of individual renown.
| Name | Summary |
|---|---|
| Bravillion | Bone Devil; Sinister Seven tactician. |
| Serevan | Shapeshifting soul-cultivator devil, Baator Conglomerate. |
| General Anxiety | Leader of the Legion of Nightmares. |
| Lady Rocky | Ascended demoness, formerly of the Notable Fiends. |
| Cockatrice Demon | Young demon terrorizing a village. |
| Granny Water Mother | Fiend and demoness based on Shuimu Niangniang. |
| The Hollow Sovereign | Undead patron (lich); identity unknown. |
| Shenmi | Undead; human in life. |
| Sorcha Zall ag | Ancient vampire queen. |
| Qephubuoli | A dragon fused with an Elder Brain; cosmic-scale puppet-master of the illithids. |
| Mordrakas | Illithid arcane lieutenant of Tah’Caluss Yorn. |
| Mo Ren | Tiger Demon wearing a mask to hide its true face. |
| Menace | Warforged construct; deceased. |
| Grooby | Bullywug spellcaster, Sinister Seven’s “wild card.” |
| Sir Kaldrfjell | Centuries-dead Trevaldan knight, now a Death Knight guarding his sons’ tomb; still active in the Kaldrfjell Tombs. |