Cavern of Suck
An idea for you PC, I see it as pure death, I personally am not this mean to my players (Killer DMs are no fun), but I am in a bad mood today. Feel free to adjust to the capabilities of your party:
The Cavern of Suck:
Environment: A huge unlit cavern filled by an underground lake/pool, a mere 30-40' deep with about a 30-40' ceiling as well. As mentioned, dark, VERY putrid smelling (perpetual stinking cloud effect), and constantly filled with the angry buzzing of undead tainted flies (an annoying insect cloud that provides appropriate minuses to attacks, AC, and Saves).
The only obvious way to cross it is by "Ye old rickety footbridge of slime coated filth and slipperiness" (TM). Please make appropriate balance checks to avoid investigating the bottom of the lake which are increased in difficulty if you make alot of sudden movements.
Swimming is frowned upon by both "Ye old true ghoul aquatic monsters of big biting (gators, sharks, piranha or whatever tickles your boat, possible giving them a spring attack for a "bite on the move")" (TM), and the very nature of the lake, which is a writhing soupy mass of "Ye old undead-corrupted maggots of stomach unsettling and small biting" (TM) whose undead taint makes them crave living flesh rather than the dead rotting flesh that normal law-abiding maggots crave (suffer a 1d6 or so for every round immersed in this ickiness). And for the piece de resistance, a true ghoul roper colony that is both perched among the stalagtites above (and in this natural cover, it is quite possible to confuse and overestimate actual number of ropers) t and the floor of the lake (the "soup" making great cover and concealment for the bottom ropers) to assist you in the crossing of the bridge (and to snag you if you are so sensible as to try to fly across). It is quite possible that if you are quite resistant to the idea of being dragged anywhere that more than one flesh starved roper will vie for your affections and you could be subject to a rend attack as a ceiling roper and a lake bottom roper play tug of war with you. If you fear that your party will simply teleport across and miss all the fun, putting a warded door on the other side is recomended.
This whole thing is fairly dangerous, and probably a tad overboard on disgusting (please adjust to what you feel tasteful), as for creepy, I think the buzzing of the flies and the chittering and roiling of the "soup" is particularily disturbing, and if the ropers hold off their attack until the party reaches the middle, the sudden suprise of an attacking swarm of slimey paralytic tentacles ought to scare the bejeezus out of them (be sure to have a moment of silence before the attack to let them know with dread that SOMETHING is coming). You can enhance this by putting up a tenacious permanent darkness effect, but I think it is a bit much.
A resourceful party SHOULD be able to meet this threat, if they are quick on their feet, and more concerned with "getting the heck out of there" than "killing da monsters". The longer you spend in this death trap, the more likely you are to be dragged under and drown and eaten from multiple sources. This should be a big XP encounter, and might serve as a main line of defense for big bad guy. Oh yeah, and put some frickin lazer beams on their heads already...
Regards
Carl W. Rowe