We'll start off with the necropede. It's in the story hour
somewhere around here, posted on 3/21/02.
The necropede was something I cobbled together at almost the last minute. I wanted a monster that could burrow, that was scary, and that the PCs wouldn't expect. I thought, "What about ghoulish umber hulks - nah - or purple worms? Damn, I'm not sure yet whether or not I want the true ghoul template to work on non-humanoids. But... they have creepy necromantic flesh-altering magics, right? And what if you made a purple worm FROM a bunch of ghouls? Oh yeah, that oughta work." The bit where the skin turns around and sprouts arms didn't actually occur to me until it was already in combat... I wanted to scare the people who WEREN'T swallowed, and my general rule of thumb is that even if it doesn't hurt them, they'll remember it if it looks scary and they don't really know what it is.
That's a good rule of thumb, actually; when it isn't immediately identifiable and classifiable, it's a lot creepier. I was at a con this weekend. An otherwise decent DM was describing a haunted, haggard NPC who was slowly dying of bad dreams and con loss. Then a PC made a knowledge: arcane check, and the DM said, "Oh, it's probably a night hag. Here's a picture of one. They live in the ethereal plane, and...." Well, there goes the excitement!
Because this was cobbled together, expect some errors. I took a purple worm, slapped a true ghoulish template on it, tossed the poison stinger, added some additional grappling abilities, and went from there. But it's creepy, eh?
Necropede (ghoulish conglomeration)
Gargantuan Undead
Hit Dice: 20d12 (130 hp)
Initiative: -2 (Dex)
Speed: 20 ft., burrow 20 ft., swim 10 ft.
AC: 19 (-4 size, -2 Dex, +15 natural)
Attacks: Bite +18 melee, grappling claws +11 melee
Damage: Bite 2d8+12 and paralyzation (DC 22)/1 pt strength drain, grappling claws 1d8+6 and paralyzation (DC 22)/1 pt strength drain
Face/Reach: 30 ft. by 30 ft. (coiled)/15_ft.
Special Attacks: Improved grab, swallow whole, strength drain, paralyzation
Special Qualities: Tremorsense, undead, turn resistance +4, resistant to blows
Saves: Fort +10 (immune), Ref +8, Will +4
Abilities: Str 35, Dex 6, Con --, Int 1, Wis 8, Cha 8
Skills: Climb +14
Roughly CR 16, I think.
Resistant to Blows (Ex): Physical attacks deal only half damage to true ghouls and ghoulish conglomerations. Apply this effect before damage reduction.
Undead: Immune to mind-influencing effects, poison, sleep, paralysis, stunning, and disease. Not subject to critical hits, subdual damage, ability damage, energy drain, or death from massive damage.
A few comments:
A successful hit should do 1 point of strength drain; a creature grappled or swallowed loses one point per round, too. I actually forgot to do this in combat, so I decided that it only works when below ground. That way, when the PCs fight them in the underdark, I'll have a good rationale for it that doesn't involve me having to assign the PCs strength damage after the fact.
This type of ghoulish conglomeration requires several hundred true ghouls to create. Upon death, it splits apart to liberate approximately 80 true ghouls capable of attacks. All other true ghouls perish when the conglomeration perishes.
Everything else is pretty straight-forward, as per a purple worm. So, the question is... what would you have done differently? What other types of conglomerations should there be? *grin*