The Hell-Caverns (of Narbonne?) are stuck in my brain. Here are some monsters I started working on before I decided I needed to focus on the dungeon I'm currently running (Nightwick Abbey). This list owes a lot to the Dismal Depths as do most of my monster designs.
If I ever go back to working on this project, I'll update the list as I need to flesh out the dungeons.
Awful Rats (N) AC 14 Move 12 HD ½ Horrid rats with crow heads. On a natural 20 to hit, roll again. If the roll is again a 20, the attacked character takes maximum damage and loses an eye.
Maggot Men (N) AC 12 Move 12 HD ½ Small creatures that resemble a combination of human and maggot features. Build huts out of spittle and filth. Wield stone spears and daggers (break on natural roll of 1). Leaders have 3HD.
Frogmen (C) AC 12 Move 9/18 HD 1-1 Small, bloated toad-like humanoids. Usually waddle uncomfortable, but will occasionally jump to attack. Gains +1 to hit and damage. Love the taste of Maggot men.
Skeleton (C) AC 14/15 Move 9 HD 1-1 Undead. Ancient warriors animated using foul magic or mad science. Typically wield rusted swords and shields but 25% chance of having a bow and 3d6 arrows. Take only 1 damage from piercing and slashing weapons. Take normal damage from bludgeons.
Morlock (C) AC 14/15 Move 12 HD 1 Degenerate descendants of a technologically advanced race. Wield stone weapons (break on natural 1). 25% chance of having a bow and 3d6 arrows. Leaders have 4 HD and are often found with mail armor and steel weapons.
Robbers (C) AC 14/15 Move 12 HD 1 Hoodlums who have hidden in the dungeon. Typically outfitted in leather and shield. 25% chance of bow and 3d6 arrows. Leaders have 6 HD and wear mail.
Cur (N) AC 12 Move 12 HD 1 Mangy, aggressive dogs. Used as guard dogs by many of the intelligent dungeon inhabitants.
Mole Men (N) AC 14 Move 9 HD 1+1 Pseudo-insectoid humanoids with large claws for burrowing. Sometimes used as slaves by morlocks. Those not enslaved will kill morlocks on sight.
Creepy Crawlies (N) AC 13 Move 6 HD 2 Cleanup crew. Blanket of flesh eating insects. Hit all opponents in a 20’x20’ area as if they were AC 12. 1 in 6 chance of being poisonous. All attacks deal 1 damage, except fire which does maximum damage.
Deros (C) AC 16 Move 12 HD 2 Unfortunates who have used the Deros Machine on level 3. Have cobolt colored skin, milk-white blood, and red eyes. Attack anything that isn’t a Dero.
Ghoul (C) AC 14 Move 12 HD 2 Undead. Appear as hybrids of humans and hyenas. Surprise on 1-3 on 1d6. Touch paralyzes (Save allowed) for 3d6 rounds.
Glow Mutant (N) AC 12 Move 9 HD 2 Poor, irradiated bastards. Constantly scream and glow as a torch only green. Never surprise party. If hit is successful, target is grabbed and takes damage each round until the creature is slain.
Zombie (C) AC 12 Move 9 HD 2 Undead. They’re Zombies. Only take 1 damage from piercing weapons. Slashing and bludgeoning weapons act normally.