D&D General Monster ENCyclopedia: Flail Snail


Shirokinukatsukami fan
This is a series of articles about specific monsters from D&D’s history. Each entry takes a look at the origin of one D&D creature, and tracks its appearances and evolution across different editions. This entry covers one of the creatures associated with the Trickster Gods of Omu in Tomb of Annihilation: the flail snail. It originally appeared along with a number of other creatures in a combined Tomb of Annihilation article.​

What might inspire someone to turn the lowly snail into a D&D monster? One possibility is a trope dating back to 13th and 14th century Europe. As documented by the British Library, in the illuminated manuscripts of the time it is not uncommon to find pictures of knights fighting snails drawn in the margins.​


Knights vs snails, images from the British Library (c.1300-1340)​

Scholars remain uncertain about the significance of these pictures. The most likely explanation is that the snails are a symbol of the Lombards, a Germanic people who ruled Italy in the early middle ages, who were vilified for their treasonous and non-chivalrous behavior. There’s no evidence that the creator of the flail snail had seen any of these pictures, but as the Fiend Folio was a British production, it is at least a possibility that the designer was aware of this historical basis for aggressive fantasy snails.​

1st Edition
The flail snail first appeared in the Fiend Folio, the gift that keeps on giving when it comes to unusual creatures. It is credited to Simon Tilbrook. The flail snail is a large (8’ high) mollusc with 4-6 club-like tentacles that it flails wildly at everything in its path. Although classified as a mollusc, a flail snail is apparently a silicon-based life-form. It is immune to fire and poison, but hypersensitive to light. For this reason, it is usually encountered underground or at night. It is a very rare creature, with no lair. It is of neutral alignment and does not accumulate treasure.

Each tentacle is treated as a 1 HD creature (potentially doing 1-8 damage) and they must all be destroyed to kill the beast. The armored body of the snail is nearly impossible to hit (AC-8), but any damage to the body kills the snail outright. If all of its tentacles are defeated, a flail snail withdraws into its shell and wails loudly and pitifully as it dies, a process that takes 1-3 turns. These loud cries have a 50% chance of attracting a wandering monster.​


Fiend Folio (1981)​

The most interesting part of a flail snail is its colored shell, which protects against magic much like a robe of scintillating colors. Spells directed against the snail might be deflected back at the caster (10%), fail completely (20%), work normally (30%), or malfunction (40%). A malfunctioning spell will be altered in some minor manner and be reflected at the nearest bystander.​

2nd Edition
For its 2nd Edition update, the flail snail shares a page with the sea snail in the MC5: Monstrous Compendium Greyhawk Appendix. Flail snails are still silicon-based here, and yet also distantly related to ordinary garden snails. Clearly, in D&D, being a life-form made from a completely different base element is no barrier to being taxonomically related.​


MC5: Monstrous Compendium Greyhawk Appendix (1990)​

There is more color in the description, with the shells “masses of neon blues, reds, greens, and yellows” and the rubbery flesh “gray-blue”. Flail snails eat lichen and algae and secrete a substance from their mouths to loosen these plants. Females give birth to 1d3 live young, which doesn’t make any sense for a genderless snail. But maybe silicon snails are an exception and do have genders. Probably best not to dwell too much on this. Snails become adults after four years and live up to twenty years. The leading cause of death for flail snails appears to be “hunted by adventurers for their shells” which is rather sad.

The flail snail’s stats block confirms that it is a solitary creature with 4-6 hit dice, depending on the number of flailing tentacles. These tentacles end in knobbly hardened lumps of flesh each weighing some ten pounds, and still do 1-8 points of damage with one attack per tentacle. It can split the attacks between no more than two opponents and cannot reach someone standing directly behind it. The flail snail’s body now has additional hit points equal to the total of the tentacles. Flail snails also have two shorter sensor tentacles with which they are able to detect motion up to 20 feet away. They aggressively defend themselves if attacked, until their opponent withdraws from sensor range. If left alone, flail snails are peaceful, herbivorous dungeon dwellers.

The mechanics of the shell’s deflection are the same as in the Fiend Folio, as are the requirements to kill the creature (destroy all the tentacles and then spend up to half an hour fending off wandering monsters attracted to its death wails). Flail snails remain immune to fire and poison, and still dislike bright light.​


Dragon #258 (1999)​

The Ecology of the Flail Snail in Dragon #258 adds a lot of additional flavor to the beast, but more importantly it declares the previous lore of flail snails being silicon life-forms with multiple genders to be erroneous, and confirms that they are, in fact, hermaphroditic gastropods that lay eggs and not live young. The article goes on to describe in considerable detail the love darting ritual flail snails engage in when mating. This involves the snails slowly circling each other, rubbing their heads and feet together and then firing darts of sperm into their mate’s genital pore. A dozen or so fertilized eggs are usually hidden in a crevice, but only a few hatch, eating their own egg shells when they do.

A baby snail grows from ten inches to adult size within four years, and is looked after by a parent for about half that time before going off on its own. Snails dwelling above ground estivate (the equivalent of hibernation for slimy and scaly creatures) during winter months, after first engaging in an eating binge. A flail snail’s shell expands constantly as it grows, with new material added around the head.

Flail snails rely on their smaller sensor tentacles to “see”, but this isn’t much more than detection of movement, light and dark in a limited range of 20 feet. The sensor stalks also have olfactory organs which give it an excellent sense of smell, and can sense movement by monitoring changes in air currents. This combination makes a flail snail immune to most vision-based illusions, and while light will blind it, this gives it a limited -1 penalty to its attacks.​


Dragon #258 (1999)​

The flailing tentacles are knobbly rather than spiked, because spikes would damage the inside of the snail’s shell when it retracts its head. The tentacles are in constant motion, moreso when the creature is agitated. They can be used to smash through wood up to an inch thick, requiring wooden shields to make a save or be shattered when struck by a snail.

Fire damage is negated both by the shell and protective mucus layer. This is secreted from the snail’s foot, and also aids in locomotion, making a snail easy to track. Flail snails shun bright light because it dries out this mucus. Salt can be used as a weapon and enough of it does 2d4 damage when thrown and a further 1d4 damage the next round. Poisons are negated by natural antitoxins in the snail’s blood.​


Dragon #258 (1999)​

Flail snails are not aggressive unless approached, and even after being attacked they will not continue to fight if an opponent retreats. The mournful wail a flail snail makes as it curls up in its shell to die is the only time it ever makes a sound.​

3rd Edition
As there was no official flail snail for 3rd Edition, snail fans needed to turn to Necromancer’s Tome of Horrors which had a d20 flail snail update and a fairly goofy illustration. This was based on the version in ENWorld’s Creature Catalog.​

4th Edition
For 4th Edition, the flail snail was relegated to the same April Fool’s adventure as the al-mi’raj. The “stale trail flail snail” as this version is called, has a slowness aura and two flail tentacle attacks, each of which does 1d10+3 damage. If both hit, the target is knocked prone. It doesn’t have as good an armor class as earlier snails did, but it gains 5 damage resistance to weapon attacks, and it has 68 hit points. Once the snail has lost half of its hit points, the shell shatters, reducing its armor class and removing the damage resistance. At this point, the snail can emit a flail snail wail which does 2d10+2 damage to all nearby opponents. The 4th Edition flail snail remains slow (speed 2) and its shell seems to have no magical abilities at all.​

5th Edition
The flail snail was updated to 5th Edition in Volo’s Guide to Monsters, and received an entire page all to itself for the first time. It is described as a creature of elemental earth (and has the elemental type). The flail snail’s diet has changed to match this, as it now moves slowly along the ground consuming minerals (rocks, sand and soil), and leaving a trail that quickly solidifies into a glass-like substance. This substance is harvested to make windows and other glass objects, and there is apparently a living to be made following a flail snail to collect its glass.​


Volo’s Guide to Monsters (2016)​

The role of the poor flail snail as something to be hunted for parts is emphasized even more than previously, and there is a whole sidebar on using the shell. Presumably shell hunters sometimes come into conflict with the glass harvesters, who would have an interest in keeping the snail alive.

In 5th Edition, the snail always has five flail tentacles and 5 hit dice (52 hit points). It loses one tentacle whenever it takes 10 or more damage in one go, but it can regrow tentacles (in 1d4 days) as long as they aren’t all destroyed. If it loses all its tentacles, the snail retreats into its shell and begins to wail loudly for 5d6 before dying. A regenerate or similar spell can stop it from dying during this period.

The flail snail’s senses have improved; it gains darkvision and tremorsense out to 60 feet. The flail snail remains immune to fire and poison. It has as many attacks as it has flail tentacles, but these must all target the same foe. Each does 1d6+3 points of bludgeoning damage. It has an armor class of 16, but can withdraw into its shell to boost this to 20. It has a speed of 10 ft, the same as it had in 4th Edition.

The colorful shell gives the flail snail the antimagic shell ability. This gives the snail advantage on saving throws against spells, and any spellcaster disadvantage on attack rolls for spells. A successful save by the snail causes the spell to be reflected back at the caster (one third of the time), or converts the spell energy into a destructive burst causing 1d6 force damage to all within 30 feet of the snail (also one third of the time). The rest of the time, the attack spell simply fails with no additional effect. The snail gains one new shell-related ability, and that is an offensive burst of scintillating light from the shell, which stuns those closest (within 30 feet), and puts those slightly further away (up to 60 feet) at a disadvantage. The flail snail can only use this ability once, and must then rest to recharge it.

Mordenkainen Presents: Monsters of the Multiverse updates a variety of creatures, including the flail snail. Here, several changes have been made to the version in Volo’s. First, the antimagic shell is simplified so that a successful save against an incoming spell is always converted into a destructive burst; there is no longer a chance for the spell to be reflected back at the caster. Second, when the flail snail loses all of its tentacles, it no longer retracts into its shell to wail loudly for up to half an hour. Given that this isn’t an ability particularly relevant for combat, it’s easy to see why it was cut, but it results in a slightly more bland creature. The damage inflicted by a flailing tentacle has also dropped slightly (from 1d6+3 to 1d4+3). Finally, if the flail snail retreats into its shell to gain a bonus to armor class, it is now treated as restrained, which it wasn’t previously.​

Flail snail parts
A flail snail shell retains its magical properties for up to six months after the snail’s death, according to the Fiend Folio. Once past any guilt adventurers might feel from removing the wailing resident, the shall makes an unwieldy and heavy (250 lb) yet valuable (5,000 gp) treasure.

MC5: Monstrous Compendium Greyhawk Adventures Appendix clarifies that a flail snail shell weighs between 250 and 300 pounds and can be turned into one or two +2 shields, which reflect magic for 1d6 months, after which they become merely +2 shields. Ground shell is a required component for the creation of a robe of scintillating colors. Dragon #147 notes that a mere 300 gp of powdered shell will also grant a +3 saving throw bonus against the volley spell, a spell bouncing dweomer from the 1st Edition Unearthed Arcana.

As if there were not already enough reasons for heartless mercenaries to hunt down flail snails, the Ecology provides two more. When ground up and mixed with blood, the stomach and liver of a flail snail are ingredients for an elixir of health, and flail snail skin (with the mucus coating) can be ground finely to use for potions of fire resistance. Flail snail mucus can be used to create potions of climbing that both taste disgusting and take twice as long to drink as a normal potion.

In Volo’s Guide to Monsters, the shell has the same statistics as in the original Fiend Folio entry. It weighs about 250 lbs and can be sold for 5,000 gp. A skilled armorer can now turn the shell into three shields, each of which has the antimagic shell trait described above. This fades after one month, but the remaining shield can be made into a spellguard shield. Ground flail snail shell is also used to make a robe of scintillating colors; it is added to the dye while the robe is being made, and also used as a material component in the enchanting ritual.​

Forgotten Realms
The flail snail doesn’t seem to have had a presence in the Forgotten Realms prior to Volo’s Guide to Monsters, but it has appeared a few times since then. The Barber of Silverymoon, a free adventure released with Dragon+ #12, has a plot which hinges on Jooge Nopsmoth, a talented barber getting into debt in order to be able to buy a flail snail, so that he can use its colorful secretions in hair dyes. He bought the snail from traveling wizards six months ago for 10,000 gp, but has not been able to repay his loan. The snail is now mostly tame, but doesn’t like strangers. Jooge and his daughter Mops know a soothing song which they can use to calm it down. This is a fun little adventure, but the premise of the plot seems flawed. While a flail snail is colorful, it doesn’t secrete anything colorful. It secretes only a clear substance used to make glass. Still, this is an adventure which includes a magical blow-dryer and a prismatic coloring machine that taps into a “dimension of pure color”, so perhaps it shouldn’t be taken too seriously.

Flail snails can be found in ruins, swamps and some parts of the jungle in Chult, according to the Tomb of Annihilation. They can also be found on the Snout of Omgar, an island off the southeastern coast of Chult, according to The Tortle Package supplement.​


Unkh’s symbol, Tomb of Annihilation (2017)​

Unkh is one of the trickster gods of Omu, and takes the form of a flail snail. She is self-absorbed and indecisive.​

Despite appearing in the Monstrous Compendium Greyhawk Appendix, flail snails seem rare in the setting. There is an aggressive one in the ruins of Castle Greyhawk, according to WGR1: Greyhawk Ruins.

As well as an obligatory appearance on the Plane of Silly and Unused Monsters in WG7: Castle Greyhawk. There is also a hasted flail snail mowing its way through the endless Eternal Autumn Woods on the fourth level of the dungeon. Killing the snail summons a group of four floating men in oriental garb. This situation raises far too many questions, not the least of which is why is the flail snail on the Plane of Silly and Unused Monsters when it is used elsewhere in this very adventure?​

The Spelljammer setting probably does have flail snails — the initial boxed set has a throwaway mention of a paladin being eaten by a flail snail in a distant crystal sphere — but what it doesn’t have, alas, is the Flail Snail ship, a prototype of which is illustrated below.​


“Flail Snail”, Dragon #192 (1993)​

Designed by a gnome, Neg’s wondrous power flail is described as a “momentum-based enemy demolition device”. It is powered by perspiring gnomes with hand cranks connected to the two huge metal weights on chains by means of gears and rubber bands. Although it is designed to be built onto the prow of any spelljamming craft, Neg’s prototype assumed that a nautiloid would be used. He submitted plans for the Flail Snail to the mind flayer embassy on the Rock of Bral, but the illithids politely sent them back.​

The flail snail is figure #38 in WizKids’s Icons of the Realms: Fangs & Talons set of prepainted minis.​


Icons of the Realms: Fangs & Talons (2020), image from MinisGallery

Computer games
In the Neverwinter computer game, the flail snail is available as a mount.​


Neverwinter animation (2015), image from arc games

Animator Benjamin Norcross wrote a blog article on the process of animating the snail for the game which includes several gorgeous pieces of concept art.​


Neverwinter concept art (2015), image from arc games

Comparative statistics

Fiend Folio, p38, 121 (July 1981)
WG7: Castle Greyhawk, p47, 78 (January 1988)
Dragon #137, p21, Treasures of the Wilds (September 1988)
Dragon #147, p24-25, Variety, the Spice of Magic (July 1989)
Spelljammer, AD&D Adventures in Space, p11 (September 1989)
MC5: Monstrous Compendium Greyhawk Appendix (April 1990)
WGR1: Greyhawk Ruins, p22-23 (July 1990)
Dragon #192, p24,Weapons of Mass Destruction: On Sale Now! (April 1993)
Dragon #258, p58-63, The Ecology of the Flail Snail: The Price of Flailure (April 1999)
The Tome of Horrors, p138 (November 2002)
Fool’s Grove Delve, p6 (April 2009)
Neverwinter (2015)
Volo’s Guide to Monsters, p144 (November 2016)
The Barber of Silverymoon, p2-4, (February 2017)
Tomb of Annihilation, p194, 200, 220, 256 (September 2017)
The Tortle Package, p5-6, 10, 18 (September 2017)
Icons of the Realms: Fangs & Talons, figure 38/45 (November 2020)​
Mordenkainen Presents: Monsters of the Multiverse, p126 (May 2022)


Neverwinter concept art (2015), image from arc games

Other ENCyclopedia entries
Visit the Monster ENCyclopedia index for links to other entries in this series.
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41st lv DM
Gods I love monsters out of the 1e FF..... :)
I find it most amusing that the thing wails loudly for 1=3 turns as it dies. Lol. The final FU to the adventurers after they've expended resources beating it down & maybe being affected by their own spells. "Fine. Kill me. But I'm going to tell everything exactly where to find you!"


Gods I love monsters out of the 1e FF..... :)
I find it most amusing that the thing wails loudly for 1=3 turns as it dies. Lol. The final FU to the adventurers after they've expended resources beating it down & maybe being affected by their own spells. "Fine. Kill me. But I'm going to tell everything exactly where to find you!"
I love the mental image of a bunch of adventurers piling the bloody shell with cloaks and blankets in an attempt to muffle the sound.


Flail snails are one of my favorite low-level monsters. I like the sheer weirdness of them, and their abilities seem likely to be pretty tough for an appropriately-leveled group. I say "seem likely" because, although I've used them in a couple of adventures, I've never had a fight with one really happen as planned. But the magic reflecting shell is likely to be a nasty surprise for some, and those five flail attacks seem like they could take out a melee PC pretty fast. It might even work as a solo boss against a level 2-3 party?

Has anyone here actually run a combat with a flail snail against a group of appropriate level, and if so, how did it go?


I've used a flail snail twice now, in two different campaigns. In the first, it was a "bystander" obstacle in a three-way fight between the PCs, stone giants under the effects of hallucinogenic spores, and the invading myconids (and basidirond) that had invaded the giants' caverns. The PCs mostly avoided the flail snail and concentrated on their primary enemies, but eventually took it down with a glaive and arrows from afar.

In the next campaign, the PCs avoided it altogether - by that time they had already met and befriended the flumph colony using the flail snail as a handy lair guardian against foes who couldn't fly up to the flumph cavern entrances.



Scion of Murgen (He/Him)
This is a much faster snail than it was previously, with a speed of 10 ft. Its senses have also improved; it gains darkvision and tremorsense out to 60 feet. The flail snail remains immune to fire and poison. It has as many attacks as it has flail tentacles, but these must all target the same foe. Each does 1d6+3 points of bludgeoning damage. It has an armor class of 16, but can withdraw into its shell to boost this to 20.
A wonderfully thorough article. Really lovely!

Re: this brief passage on the 5E stats, I will quibble/clarify that the 10'/rd speed of the 5E Flailsnail is identical to the speed 2 of the 4E Flailsnail (two 5' squares/round). The 3" speed of the 1E Flailsnail equals 30'/round, although one could certainly argue that this is much slower in real terms, given 1E's one minute combat rounds!

Interesting that the 2E stat block summary you've given lists the speed as just "3". As I recall 2E switched from wargame scale inches to units of feet, but normally they actually included the distance notation rather than having an unadorned integer.


Shirokinukatsukami fan
Re: this brief passage on the 5E stats, I will quibble/clarify that the 10'/rd speed of the 5E Flailsnail is identical to the speed 2 of the 4E Flailsnail (two 5' squares/round). The 3" speed of the 1E Flailsnail equals 30'/round, although one could certainly argue that this is much slower in real terms, given 1E's one minute combat rounds!

Interesting that the 2E stat block summary you've given lists the speed as just "3". As I recall 2E switched from wargame scale inches to units of feet, but normally they actually included the distance notation rather than having an unadorned integer.
Good catch, thanks! I've fixed that paragraph. The 2nd Edition Monstrous Compendium entries all seem to be just numbers, without any other notation, so the flail snail's "3" isn't unusual.


Moderator Emeritus
I love all things Fiend Folio and the Flail Snail is up there as a fave of faves.

The PCs in my "Out of the Frying Pan" 3E campaign ran into one with the fire elemental template slapped on.

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