If you ever plan a visit to Central America—and I highly suggest that you do—take care to avoid the Fer-de-Lance. A pit viper with a particularly nasty bite, it is arguably the most dangerous snake in Central America. It is defensive, unpredictable, and it lacks all fear of humans. It is the leading cause of snakebite in almost every Central American country, and its bites can cause gangrene. Because of its reputation, it has earned several nicknames, the most striking being “the Costa Rican landmine.” In short, it is not a creature to be toyed with.

An adventuring party would rip it to shreds.

The blessing and the curse of Dungeons and Dragons is that the multiverse is populated with large, dangerous monsters that can challenge our heroes. While there is no end of dragons, giants, and vampires for players to fight, the game’s smaller threats get fairly short shrift. Sure, the party may have cleared out the orcs from the cave before going to sleep, but did anyone remember to check their boots for scorpions in the morning? Most groups simply wouldn’t have to, because mundane scorpions, snakes, and spiders are a non-entity at a lot of tables. It’s easy to see why: a black widow spider may have a powerful venom, but since there’s no universe in which it has more than a single hit point, there’s no use running it against players that will swat it like…well, a bug. Unfortunately, this can leave the world feeling a little underpopulated, like part of the ecosystem is missing.

Enter the “creature trap.”

Most venomous animals are ambush predators: they strike without warning, usually from cover, and are toxic enough to take down prey many times their own size. At the same time, they’re also physically fragile; most adventurers could kill them without a second thought. Using the game’s built-in trap mechanics solves this paradox. It allows a creative dungeon master to reimagine a poison gas trap as a snake biting unsuspecting passers-by, or a glyph of turn to stone as the sting of a magical scorpion. Like most other traps, they can be spotted and avoided with a sufficiently high Perception or Investigation check; the only difference is that these traps are organic, not mechanical.

Below, I’ve created three illustrative examples, all of them venomous snakes. Use them in your own games, or as starting points for your own designs.

Steelskin Adder

Notable for its dappled grey scales and milk-white eyes, the steelskin makes its home in volcanic caverns, ruined fortresses, and other places where it can easily blend in with the surrounding stone. Nearly blind, it relies on its ability to sense body heat and vibrations to ambush nearby prey. It spends most of its time curled up in dark corners or under old furniture, waiting to strike unsuspecting creatures with blinding speed.

Steelskin venom is a powerful hemotoxin. A player who suffers a bite must make a DC 15 Constitution saving throw. If they succeed, they suffer 1d4 piercing damage from the bite, but no other ill effect. If they fail, they suffer an additional 2d6 poison damage, and are considered poisoned until the end of their next long rest. Over the next hour, the bitten limb burns and swells as the blood coagulates in their veins until the limb becomes immovably stiff. The player has disadvantage on all Dexterity saving throws and suffers a -2 penalty to their armor class until the end of their next long rest. Casting lesser restoration will negate the effects of the poison, but will not heal damage already taken.

Black Tommygoff

The black tommygoff, also known as “The Bastard of the Bush,” makes its home in lush rainforests and jungles. Though its scales are iridescent green, it is its black mouth that gives the snake its name. A long, thin tree-dweller, the tommygoff is often mistaken for an errant vine or tree branch. It will not attack unless it feels cornered, but if it does, it strikes multiple times, injecting more venom into the victim’s bloodstream with each bite.

The initial bite is painful enough, but the snake’s real danger lies in its neurotoxic venom. Tommygoff venom causes encephalitis, and brain swelling can quickly reach dangerous levels. A player who is bitten makes a DC 15 Constitution saving throw. If they fail, they are poisoned until the end of their next long rest, and they have disadvantage on all Intelligence and Wisdom saving throws for the next hour. After an hour, the player must make DC 13 Constitution saving throw. If they fail a second time, they immediately drop to 0 hit points and fall unconscious. If that player is revived, the disadvantage effect remains. A lesser restoration spell will remove the lingering effects of the poison, but will not revive an unconscious player.

Crimson Sidewinder

A pit viper found in desert environments, the crimson sidewinder is identifiable by its rust-colored scales and its unusual namesake movement. Slithering sideways up and down sand dunes, it is most active at night, preferring to sun itself on a rock during the day. While the sun is up, they are generally lethargic, and won’t attack unless provoked. At night, when they are hunting, they are much more aggressive. Those who travel the desert roads after dusk should watch where they step.

Sidewinders strike fast and without warning. A player who disturbs a crimson sidewinder must make a DC 15 Constitution saving throw. On a success, they suffer 1d4 piercing damage from the bite, but no other ill effects. On a failure, the player suffers 2d8 poison damage from the initial bite, and they are considered poisoned until their next long rest. Sidewinder venom affects blood’s ability to clot; the player has disadvantage on all Constitution saving throws until the end of their next long rest. Additionally, if they suffer bludgeoning, piercing, or slashing damage while poisoned, they take an additional 1d10 damage at the start of their next turn as the wounds continue to bleed. As with other natural poisons, casting lesser restoration will negate these effects, but it will not heal damage that the player has already taken.

There are as many serpents, arachnids, and carnivorous plants in the multiverse as there are stars in the sky, so I encourage you to design your own devious creature traps for your players. If you’re inspired to create your own, feel free to share in the comments. The only limit is your own imagination.

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