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Living Traps
Wandering Monsters
By James Wyatt

B ack in March, I discussed various dungeon denizens that haunt the underground environments that form the backbone of many D&D campaigns. I covered many oozes, the roper, the otyugh, and the mimic.

So let's change our focus this week back to a couple of monsters in a similar category, paying particular attention to those close in concept to the mimic. I'm thinking about creatures that blur the line between monster and trap (and, in fact, have appeared on both sides of the line in various editions of the game). We'll look today at the trapper and the lurker above, the piercer and the darkmantle, the green slime, the shrieker, the ear seeker, the throat leech, the rot grub, and the yellow and brown mold. That's quite a list, isn't it?


The lurker (originally known as the lurker above) is a flying creature that resembles a manta ray, except that its grayish belly is textured like stone. As you might guess, it clings to the ceiling of caverns and dungeon rooms so that it can drop down on creatures that pass below it. It engulfs its victims, constricting and suffocating them. Originally, it was 20 feet in diameter, so I think the assumption was that it would drop down on a whole party of adventurers. It got smaller in 3rd Edition (in the Underdark book), and it could grab only one person at a time.

The trapper is similar except that it lurks on the floor. It can make a protrusion that looks like a box—although that's awfully mimic-like. As with the lurker, when creatures walk over it, it curls up and squeezes them to death. Traditionally, it has immunity to fire and cold, which the lurker does not share.

These could be the same creature, with the choice of whether to lurk above or below being up to the individual. The two creatures could also be some kind of sexual dimorphism, or maybe a lurker needs time to refill the gas-filled sacs that allow it to fly after it has dropped down onto prey. Perhaps lurkers grow up to be trappers—after they grow beyond a certain size, the gas that lets them fly can't lift their bulk any more, but they also gain that immunity to fire and cold. They could also remain separate creatures.

It's not clear how or whether these creatures can attack creatures that aren't caught inside them when they trigger. They're not amorphous, like an ooze, so it's hard for me to imagine one extending a pseudopod to grab a creature outside its suffocating folds. I suppose they can lash out with a "wing" to do bludgeoning damage, but I think if you don't get caught in the initial attack, you're safe from being squeezed to death. And if it attacks something it's not constricting, that might give a creature inside a chance to break out.

Fundamentally, these creatures are a lot like traps. They're hard to detect, and the way to deal with them after you've triggered them is to deal damage to them.

Piercers and Darkmantles

These monsters are similar in concept to the lurker—monsters that look like normal features of the ceiling (stalactites, in this case) that drop down on creatures passing below. In 1st Edition and 2nd Edition AD&D, they were piercers, and dropping down on their prey was their only attack. In 3rd Edition and 4th Edition, they became darkmantles, a sort of flying octopi that curled up into a stalactite-like shape. (The 3rd Edition Monster Manual included a nod to the old piercer, suggesting that the darkmantle had "recently evolved from a similar but far less capable subterranean predator.")

I've heard some people around here saying we should bring back the piercer and make these separate monsters again. In that case, the piercer works a lot like a trap, again—if it hits you when it drops, it does damage (and sometimes a lot of damage, depending on its size), but otherwise it's not much of a threat. The worst thing about them is that they tend to cluster in numbers.

Darkmantles, on the other hand, are more like monsters. They lurk on the ceiling and drop down on creatures below, but they actually fly toward their prey and attempt to engulf the victim's face, suffocating it. They can also create globes of darkness to hide their approach.

They make sense as separate creatures, given the differences between them. But I can also imagine the darkmantle as a larval form of the piercer. As it grows, it also hardens, until the point where it can no longer fly. It might be interesting to let the piercer keep the darkmantle's ability to create darkness, making it perhaps slightly less helpless after it has fallen to the ground.

Green Slime

Continuing the theme of dropping down on creatures from above, the green slime can't actually move, but it can make itself drop from the ceiling. I think its lack of movement is the reason that it turned, in 3rd Edition, from a creature into a trap. Mostly, it relies on unwitting creatures touching it—putting a hand on a slime-covered wall in the dark, perhaps, or stepping into a puddle of it on the floor. (Presumably, it grows along hard surfaces regardless of gravity—it can't move from the floor to the ceiling, but it can grow up the walls to the ceiling.)

Green slime is highly corrosive, going through heavy armor in a matter of rounds and dissolving flesh, turning its victims into more green slime. The only hope for a creature infected with green slime is to scrape it off quickly, cut it away, freeze it, or burn it—all of which are certain to do more damage to the victim beyond what the slime is already doing.

Green slime is hard to root out. Even after it has been burned away, the slime can sometimes return from long-dormant spores. Dwarves have been known to seal off mining tunnels infected with the stuff rather than keep trying to fight back new growth.


I had a delicious portobello mushroom sandwich recently. I wonder whether a shrieker would taste as good, sautéed in butter with garlic salt and balsamic vinegar? Apparently purple worms and shambling mounds find them delicious, even without seasoning.

Shriekers are big (4 to 7 feet tall) fungi that wander very slowly through underground areas. They're saprophytes, feeding on dead and decaying organic matter—such as the corpses of creatures killed by violet fungi, which they strongly resemble. (Violet fungi, however, have branches they can use to lash out at prey.) As its name suggests, the shrieker makes a tremendous racket when it senses light or movement, hoping to draw in other creatures so that they'll fight each other. After the battle, the shrieker can feed on the corpses of whichever side came out the worse.

Due to how they operate, shriekers by themselves are more of a nuisance than a monster. You can shut one up by hacking it to pieces (though it takes considerably more effort than slicing a portobello), but it grows quiet within 3 rounds anyway. These creatures are basically an excuse for the DM to bring some encounters to you.

Don't Touch That!

Speaking of excuses for the DM to do nasty things to you, these three monsters are really just mean. I don't mean the monsters themselves are mean, but any DM who uses them clearly has a grudge.

Ear seekers are insects that live in wood and burrow into your ear when you listen at the door. They eat wood, but they lay their eggs in warm places. Naturally, the hatching larvae burrow deeper into the warm places, killing the host within 1d4 days. In other words, this monster is for DMs who are tired of players having their characters listen at every door. I think it would have the opposite effect, though, by encouraging players to have their characters spend even longer at every dungeon door, searching for ear seekers before listening—or listening through a cone with mesh over the wide end. Ugh.

And it's not a monster. It's a parasitic infestation. You deal with it by casting cure disease.

Throat leeches look like twigs floating in water. If you drink the water, the throat leech gets lodged in your throat, dealing 1d3 damage per round until it's full and bloated. Oh, and it might choke you. The lesson here is make sure you carefully filter the water you drink, because the only way to get rid of a throat leech is to pierce it with a hot wire, making it burst—in the back of your throat. And a clumsy person might burn you with the wire instead of burning the leech.

Ugh. This is another trap, basically, and one with the same misguided motivation—make sure the characters take extra precautions to do mundane things in the world, thus slowing the game to a grinding halt.

Rot grubs tell players, "Don't go digging around in filth!" When you go searching for the otyugh's treasure at the bottom of the middens, these maggot-like creatures might burrow into your flesh. Oh, and you might not even notice, because of the anesthetic slime they secrete. And they burrow toward your heart, killing you in half an hour or less unless you burn them out or have a cure disease spell cast on you.

Obviously, I think these three monsters do more harm to the game than good. I'd rather see them on a list of diseases or parasitic infections than in a Monster Manual.

Of course, I might be wrong, and I'm open to argument—in the comments!


Yellow mold sort of falls into the "don't touch that" category, too. If "touched roughly," it might (50 percent chance) release a cloud of toxic spores—save or die. It might be interesting as a terrain effect in a tactical game—try to push the monsters into the mold before they push you in. And keep your distance so you don't get caught in the spore cloud. For those seeking to kill off yellow mold, fire destroys it.

Before I move on, let's not forget the possibility that a very large colony of yellow mold might be sentient. It can project its spores 60 feet and use suggestion to draw people into its area. And it can eat your intelligence. It might even have psionic abilities.

Brown mold is more interesting, I think. It feeds on heat, so it deals cold damage to creatures within 5 feet. Fire makes it grow, so don't try to apply what you've learned from one mold to a different kind of mold. Cold damage can kill brown mold, though. The cold of a brown mold is, I think, a terrain effect that can add something to an encounter.

What Do You Think?

Previous Poll Results

First off, are there creatures I’ve described here that you don’t ever want to see in D&D again? (Check all that apply.)
Aarakocra 147 14%
Dire corby 317 31%
Hawk-headed kenku 339 33%
Crow-headed kenku 199 19%
Crow-headed or long-nosed tengu 337 33%
Nagpa 268 26%
Raptoran 405 39%

Should the aarakocra absorb the raptoran and do more with the elemental pact?
No, neither one belongs in the game. 49 5%
No, the raptoran should kill the aarakocra and take its stuff. 109 11%
No, they should remain two different creatures. 221 21%
Yes, and they should have a pact with djinn. 141 14%
Yes, and they should be connected to the Rod of Seven Parts and the Wind Dukes of Aaqa. 151 15%
Yes, and the DM should be encouraged to shape the pact to fit the campaign. 329 32%

What do you think of the dire corby’s connections?
They’re weirdly descended from drow and birds. 40 4%
They were bred by the drow as slaves. 126 12%
They’re the product of natural evolution of predatory birds in the Underdark. 229 22%
They’re tied to Pazuzu and rivals of the drow. 465 45%
Other. 111 11%

Should I have taken the gyerian more seriously?
Oh good grief, no. 716 70%
Maybe. There could be cool stuff there. 231 22%
Yes, I can’t believe you dissed my favorite monster! 47 5%

Thieving, scurrilous kenku—hawk heads (1E–2E) or crow heads (3E–4E)?
Hawk heads. 219 21%
Crow heads. 443 43%
They’re two branches of the same race. 340 33%

How can we tie the kenku better into the world?
Make them fey. 438 43%
Make them related to harpies. 105 10%
Connect them to Pazuzu. 119 12%
Relate them to the nagpa. 75 7%
Other. 222 22%

Am I right to keep the tengu off to the side in Kara-Tur?
No, they should replace the kenku. 66 6%
No, they should coexist as equals with the kenku. 192 19%
No, they’re silly and don’t belong in the game. 90 9%
Yes, they’re fine for an Asian-flavored game but don’t belong in core D&D. 634 62%

Does the nagpa need more connections in the world?
Yes, a link to some other monster in its history. 114 11%
Yes, a link to a place or artifact. 115 11%
Yes, who placed the curse? 478 46%
No, it’s great as it stands. 264 26%

Overall, how do you think the descriptions of these creatures square with their history in the game?
1—Terrible: There’s so much more to these creatures. 17 2%
2—Pretty bad: You really didn’t do them justice. 30 3%
3—So-so: It makes sense, but it doesn’t grab me. 378 37%
4—Pretty good: I can see using such a thing in my game. 497 48%
5—Awesome: I might actually use some of these monsters now! 66 6%

Have you used these monsters in your game before? And how? (Check all that apply.)
No, never used them, and I never will. 71 7%
No, I haven’t used them, but I can imagine bringing them in. 360 35%
Yes, I’ve used them as allies for the player characters. 287 28%
Yes, I’ve used them as allies for friendly nonplayer characters. 184 18%
Yes, I’ve used them as opponents for the player characters. 450 44%
Yes, I’ve used them as player characters. 262 25%

James Wyatt
James Wyatt is the Creative Manager for Dungeons & Dragons R&D at Wizards of the Coast. He was one of the lead designers for 4th Edition Dungeons & Dragons and the primary author of the 4th Edition Dungeon Master’s Guide. He also contributed to the Eberron Campaign Setting, and is the author of several Dungeons & Dragons novels set in the world of Eberron.
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