5E: Monstrous Arthropods for Fifth Edition

[Cleon]

Odonatid, Giant (Imperial Giant Dragonfly Nymph)
Large beast, unaligned
Armor Class 15 (natural armor)
Hit Points 52 (7d10 + 14)
Speed 30 ft., swim 10 ft.

STR​	DEX​	CON​	INT​	WIS​	CHA​
20 (+5)​	14 (+2)​	15 (+2)​	1 (–5)​	12 (+1)​	5 (–2)​

Skills Stealth +6
Senses blindsight 30 ft., passive Perception 11
Languages —
Challenge 2 (450 XP) Proficiency Bonus +2

Ambusher. In the first round of a combat, the giant odonatid has advantage on attack rolls against any creature it surprised.

Actions

Bite. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) slashing damage and the target is grappled (escape DC 15). Until this grapple ends, the target is restrained, and the giant odonatid can't bite another target.

Death Mask (Recharge 4–6). Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 12 (2d6 + 5) piercing damage. If the target is a Large or smaller creature, the target is grappled (escape DC 15) and must make a DC 15 Strength saving throw. On a failure, the target is knocked prone, and the giant odonatid can drag the target closer and make one bite attack against it as a bonus action. Until this grapple ends, the odonatid cannot use its Death Mask attack again.

Jet Dash (Recharge 5–6). The dragonfly nymph swims up to 80 feet.


Description

Apart from their size, these larvae are no different from a standard giant dragonfly's larva (see Giant Dragonfly Nymph for details). An imperial giant dragonfly nymph grows about 8 feet long.

VARIANT: IMPERIAL GIANT DAMSELFLY NAIAD
This is the larva of a Large giant tropical damselfly (see Imperial Giant Dragonfly for details). An imperial giant damselfly naiad averages 12 feet in length and uses an imperial giant dragonfly nymph's statistics, except it is faster (30 ft., swim 30 ft.) and loses the nymph's Jet Dash action option.

VARIANT: IMPERIAL GIANT TENEBROUS & UNDERDARK DAMSELFLY NAIADS
These are larvae of monstrous damselflies adapted to live in dark environments (see Mammoth Helicopter Damselfly for details, under Tenebrous Helicopter Damselflies and Underdark Helicopter Damselflies). An imperial giant tenebrous damselfly naiad has blindsight 30 ft. and darkvision 90 ft.

An imperial giant underdark damselfly naiad uses an imperial giant dragonfly nymph's statistics, except it moves as well on land as water (30 ft., climb 30 ft., swim 30 ft.), has blindsight 60 ft. and darkvision 120 ft., and gains the following additional trait.
 Amphibious. The underdark damselfly naiad can breathe air and water.

VARIANT: IMPERIAL GIANT TERRESTRIAL DAMSELFLY & DRAGONFLY LARVAE
This is an imperial giant damselfly naiad or imperial giant dragonfly nymph adapted to live on land, although It cannot survive dry conditions for long (see Giant Dragonfly Nymph for details, under Terrestrial Giant Odonatid Larvae). An imperial terrestrial odonatid larva uses an imperial giant dragonfly nymph's statistics, except it moves better on land than water (30 ft., climb 20 ft., swim 10 ft.), loses the Jet Dash action option if it's a dragonfly nymph, and gains the following additional trait.
 Limited Amphibiousness. The terrestrial odonatid larva can breathe air and water, but it needs to be drenched in water at least once every 4 hours to avoid suffocating.

(Monster designed by Casimir Liber and Cleon on Enworld.org's General Monster Talk Creature Catalog Forum; based on the tropical giant dragonfly nymph that first appeared in EX2 The Land Beyond the Magic Mirror (1983) by Gary Gygax.)

 

[Cleon]

Odonatid, Giant (Mammoth Helicopter Damselfly)
Huge beast, unaligned
Armor Class 15 (natural armor)
Hit Points 68 (8d12 + 16)
Speed 10 ft., fly 60 ft. (hover)

STR​	DEX​	CON​	INT​	WIS​	CHA​
20 (+5)​	17 (+3)​	14 (+2)​	1 (–5)​	12 (+1)​	5 (–2)​

Saving Throws DEX +6
Skills Perception +4
Senses blindsight 30 ft., darkvision 90 ft., passive Perception 14
Languages —
Challenge 5 (1,800 XP) Proficiency Bonus +3

Evasive Flight. A giant odonatid gains advantage on Dexterity saving throws when flying and attackers have disadvantage on attack rolls against it.
 If the giant odonatid is mounted or grappling an opponent, it must make a DC 12 STR check to use Evasive Flight each time it is attacked.

Expert Aerialist. The giant odonatid has advantage on Dexterity (Acrobatics) checks when flying.

Flyby. The giant odonatid doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Keen Sight. The giant odonatid has advantage on Wisdom (Perception) checks that rely on sight.

Motion Camouflage. If the giant odonatid moves at least 20 feet towards a creature and then hits it with an attack on the same turn, that target must make a Wisdom (Perception) check against a Dexterity (Acrobatics) check by the odonatid. On a failure, the target cannot use Dodging Flight, Evasive Flight, or a similar defensive ability to avoid attacks by the giant odonatid until the start of its next turn.

Actions

Multiattack. The giant odonatid makes two attacks against a Large or smaller creature. The first attack is a legs attack. If this succeeds in grappling the target, the odonatid makes a bite attack, otherwise it makes a second legs attack.

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 18 (3d8 + 5) slashing damage.

Legs. Melee Weapon Attack: +8 to hit, reach 10 ft., one Huge or smaller creature. Hit: 8 (1d6 + 5) bludgeoning damage and the creature is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the giant odonatid can't make legs attacks against another target.

Bonus Actions

Dashing Flight. The giant odonatid flies up to 40 feet. It cannot use Burst of Speed if it used Dodging Flight after the start of its previous turn.

Reactions

Dodging Flight. If a creature of at least Small size attempts a melee attack against a giant odonatid, or the odonatid is targeted by a ranged weapon of similar size such as a giant-hurled boulder, the insect can try to dodge out of the way as a reaction. The giant odonatid makes a Dexterity saving throw with advantage (it loses this advantage when mounted or grappling an opponent). If the saving throw beats the attack roll or DC of the attack the giant odonatid takes no damage and flies up to 40 feet.
 If a giant odonatid is carrying or grappling a creature that is too heavy for the odonatid to fly with, it must release the creature to use Dodging Flight. If the odonatid is grappling a creature light enough to carry through the air, the grappled creature can make an escape check as a free action. If it fails, the odonatid may fly away with its victim.


Description

Helicopter damselflies include the longest and widest of all Odonata, with even the mundane species growing up to 6 inches in length (The giant helicopter Mecistogaster linearis) or an 8 inch wingspan (The blue-winged helicopter Megaloprepus caerulatus). A mammoth helicopter damselfly is truly enormous, typically 30 feet long, with a 30 to 45 foot wingspan, and weighs about 4,000 pounds or 2 short tons. The mammoth helicopter presented above is more correctly a Mammoth Tenebrous Helicopter Damselfly (see Tenebrous Helicopter Damselflies below). They dwarf a regular giant dragonfly (see Giant Dragonfly), although some tropical giant dragonflies are heavier and even more powerful (see Titanic Tropical Dragonfly).
 These tropical damselflies have extremely elongated and narrow abdomen, and equally slender wings that often have a spot or band of color at the end. A flying helicopter damselfly resembles a pinwheel fluttering and swirling in midair, or a hovering windmill for a mammoth giant helicopter. Their wings appear to spin around the thorax, as if the insect was corkscrewing itself through the air, an illusion that lead to the common name of helicopter damselfly.
 Helicopter damselflies live in rain forests and jungles. The normal version can be fairly common, but mammoth helicopter damselflies are extraordinarily rare due to the unusual habitats they need. This rarity has led to many legends, rumors and tall tales, a few of which might contain a few grains of truth. These stories include:

• Mammoth helicopter damselflies were created by a forgotten insect-headed god to protect its temples and worshippers. The civilization is long dead, with its cities lost in the heart of a colossal jungle, but the mammoth damselflies still faithfully patrol its ruins.
• These great insects are solitary queens, each served by a hive of lesser giant damselflies (e.g. the Giant Damselfly or Giant Tropical Damselfly), while larger ones (e.g. the Imperial Giant Damselfly) guard the queen's boudoir and the hive's treasures.
• A mammoth helicopter damselfly is an artificial species invented by a mighty wizard, solely to annoy drow elves by eating the giant spiders that drow love.

Jungle Dwellers. A mammoth helicopter damselfly is an extremely precise and agile flier, but is so gigantic it still needs around 50 feet to fly through a gap. Therefore any rainforest it navigates must have the majority of its trunks spaced at least that far apart. Their preferred habitat are spectacular jungles of mysterious and possibly magical origin that have other giant arthropods as their primary fauna. While they could adapt to other hot and humid places with suitable prey and breeding pools, the only non-rainforest habitat they're known to favor are ruined or abandoned cities with buildings tall enough to fly between. Tropical gigantic damselflies will venture into the open on short hunting expeditions or seek a new territory after being driven away by rivals, but in an open environment they are out-competed by other flying predators, particularly gigantic tropical dragonflies and kaleidoscopes of imperial giant tropical dragonflies (see Titanic Tropical Dragonfly and Imperial Giant Dragonfly, or the Mammoth Tropical Dragonfly below).
 Wings in the Dark. Many tropical odonatids like to perch in the shade of vegetation, both to hide from predators and to avoid overheating from the warmth of the sun. Helicopter damselflies, living as they do beneath the forest canopy, spend most of their lives in the shadows. When they do go out of the cover of the trees, helicopter damselflies prefer gloomy overcast conditions over hot and sunny days. Normal-sized helicopter damselflies hunt and breed during the day then rest at night, as is usual for odonatids, but the mammoth helicopter is a tenebrous giant damselfly (a monster odonatid with both blindsight and darkvision) and hunts at night as easily as day. The standard mammoth helicopter damselfly can be nocturnal (active at night), crepuscular (most active at dusk or dawn), or hunt whenever it is hungry regardless of time, depending on when its usual prey is out and about, but avoids entering bright daylight when it doesn't have to.
 Spider Hunters. Normal helicopter damselflies specialize in hunting spiders. They slowly fly up to webs and pluck off the spider or the spider's silk-wrapped prey, which are devoured in midair. A monstrous helicopter damselfly still likes to attack spider webs, but is also a generalist hunter who will snatch prey from the ground, air, and trees. Like a regular damselfly, it only catches prey it can carry through the air. That is no great restriction, as a mammoth helicopter damselfly can lift 1,200 pounds while flying, enough to carry creatures as heavy as giant spiders, average-sized brown bears and riding horses, or giant horseflies (see Giant Tabanid). Giant helicopter damselflies prefer non-flying prey and rarely engage in aerial pursuits like a giant dragonfly or giant tropical damselfly.
 Waterpit Breeders. Natural helicopter damselflies breed in phytotelmata—the pockets of water that collect in vegetation (e.g. holes in trees, hollow tree stumps, broken bamboo, cup-shaped plants like bromeliads, fallen leaves and rinds). Males compete for the best breeding spots and guard the phytotelmata, mating with females before they lay their eggs. While normal helicopter damsels might have difficulty finding a phytotelma, it is almost impossible for mammoth helicopters, since only implausibly colossal plants could hold enough water. Giant helicopter damselflies only breed in still water, so rivers and streams are not an option. Instead, the giant helicopter damselflies usually breed in water-filled pits, such as sinkholes and caves, including artificial ones like cisterns and water tanks. On average, these sites produce one adult for every 13,500 cubic feet of water they contain, and pits as small as 6,000 cubic feet can be enough for a single naiad to reach adulthood. An Olympic-sized swimming pool (~88,000 cubic feet), for example, could produce six or seven adults from its resident naiads (see Mammoth Damselfly Naiad for statistics).
 The tremendous rarity of suitable breeding sites is the primary restriction on mammoth helicopter damselfly numbers in the jungle. Some mammoth odonatids have nymphs and naiads with adaptations to reduce the limitations of breeding in water (see Giant Dragonfly Nymph for details).

VARIANT: MAMMOTH TROPICAL DAMSELFLY (DIURNAL)
A mammoth tropical damselfly have the same statistics as the mammoth tenebrous helicopter damselfly described above, except it does not have blindsight or darkvision. Diurnal mammoth tropical damselflies hunt in daylight like their smaller brethren and either have similar proportions to a mammoth helicopter damselfly, or are somewhat shorter: 24 to 30 feet long, 30 to 36 foot wingspan. Many are simply mammoth helicopter damselflies that lack the darkness adaptations of the standard variety.

VARIANT: MAMMOTH TROPICAL DRAGONFLY
Some varieties of giant dragonfly exceed even the imperial giant dragonfly in stature. A mammoth giant dragonfly is approximately 18 to 20 feet long, with a wingspan of 30 to 33 feet. It uses a mammoth tropical damselfly's statistics except for being faster (fly 80 ft., Dashing Flight 80 ft., Dodging Flight 40 ft.) and having no blindsight or darkvision. A mammoth tropical dragonfly nymph grows into as huge and deadly a predator as a mammoth damselfly naiad.

VARIANT: MAMMOTH UNDERDARK DAMSELFLY
This is a Huge underdark helicopter damselfly, called a death phantom in Common and a word meaning web killer in Undercommon. It is one of the rare few who was so successful as a naiad it matured into a full sized adult (see the Underdark Helicopter Damselflies below). Smaller underdark helicopter damselflies, commonly called ghostwings and wraithwings, are little different from the tenebrous giant helicopter damselflies of the surface, but mammoth specimens possess two abilities their lesser kin never develop—they become resistant to magic and their wings can mesmerize opponents. A mammoth underdark damselfly, dubbed a death phantom, has a challenge rating of 6 (2,300 XP) and uses a mammoth helicopter damselfly statistics, except it has blindsight 60 ft., darkvision 120 ft., and the following additional trait and action option.
 Magic Resistance. The death phantom damselfly has advantage on saving throws against spells and other magical effects.
 Hypnotic Wings. The death phantom damselfly swirls its wings in a hypnotic pattern. Every creature within 300 feet of the damselfly that can see the wings and is not another underdark damselfly must succeed on a DC 14 Wisdom saving throw or be charmed until the wings' motion ends. If a creature has Fey Ancestry and sees the Hypnotic Wings with darkvision, the trait does not give the creature advantage on saving throws against being charmed by the wings.
 The death phantom damselfly must take a bonus action on its subsequent turns to continue the hypnotic motion. It can stop its hypnotism at any time. The hypnotism ends if the death phantom is incapacitated or flies more than 60 feet on its turn (including any distance it moves with Dashing Flight or Dodging Flight). While charmed by the death phantom damselfly, a creature is incapacitated and does nothing but stare mesmerized at the insect. The hypnosis effect ends if the target takes any damage from the death phantom damselfly. If a charmed creature takes damage from a source other than the death phantom or is about to face another obvious danger, such as an approaching fire, it can repeat the saving throw. A charmed creature can also repeat the saving throw at the end of each of its turns. If the saving throw is successful, the effect ends on it. A creature that successfully saves is able to resist the hypnotism for the next 24 hours. If the creature fails a saving throw during their period of resistance against the death phantom damselfly's Hypnotic Wings, it is only partially charmed and may target the death phantom with harmful abilities or magical effects. Instead of being incapacitated, a partially charmed creature has disadvantage on attack rolls and skill checks, and the death phantom damselfly has advantage on attack rolls against the partially charmed creature.


TENEBROUS HELICOPTER DAMSELFLIES
While the mammoth helicopter damselfly is the best known of the darkvision-equipped giant damselflies, it does have smaller relatives. The majority are nocturnal, hiding in caves or the densest vegetation during the day and being active from dusk to dawn. They rarely bother humanoids, which no doubt contributes to their obscurity.
 Tenebrous helicopter damselflies tend to be relatively petite odonates no larger than small size that eat night-flying animals such as bats and stirges with the occasional unlucky lemur or rat. Medium or Large tenebrous damselflies are even rarer than the mammoth tenebrous helicopters, and most of the Large ones are actually undersized mammoth helicopter damselflies whose nymphs were unable to grow to their proper Huge size. Some tenebrous damselflies hunt in the uppermost areas of the Underdark inhabited by creatures that regularly visit the surface. These often breed in water-filled caverns and might spend most of their lives underground, but can survive outside their subterranean home, unlike the true underdark damselflies (see below). Many of these have young that can survive for long periods away from water (see Giant Dragonfly Nymph for details, under Terrestrial Giant Odonatid Larvae).


UNDERDARK HELICOPTER DAMSELFLIES
Deep beneath the earth is the Underdark, a mysterious maze of tunnels, crevices and caves. The greatest of its caverns are unbelievably vast and teem with life in forests of weird fungi and strange subterranean seas. In this sunless realm, the ecosystem is powered by dissolved chemicals, geothermal warmth, and the Underdark's own eldritch radiations.
 Some of these sunless seas and mushroom jungles swarm with shimmers of giant damselflies who explorers from the surface have dubbed Ghostwings from their eerie appearance. A ghostwing is two or three yards long, with body and legs that look so thin they're almost translucent, and to normal eyes it is colored pallid white with spots of deathly grey. However, it is actually strikingly patterned in garish hues that are only visible to darkvision—many of these darkvision colors don't even have names in Common. Despite their spooky appearance, ghostwings are relatively harmless, and mostly only attack normal bats and spiders, Tiny giant flies, and creatures of similar size. A ghostwing damselfly is a Small or Medium underdark helicopter damselfly (see Giant Damselfly or Giant Dragonfly for statistics).
 That is far from the case for the mammoth underdark damselfly, a rare monster that can reach lengths of 50 feet or more. They have many names, such as Death Phantom or Web Killer and are hated and feared by the Underdark's inhabitants, especially the drow,. Mammoth underdark helicopters show a great fondness for eating subterranean giant spiders and the drow themselves, so the dark elves go to great lengths in attempts to eradicate them, with little success. A death phantom damselfly is a Huge underdark helicopter damselfly (see Titanic Tropical Dragonfly or the Mammoth Underdark Damselfly above for statistics).
 Ghost and Phantom Larvae. The main reason the drow have failed to exterminate the mammoth underdark damselfly is ghostwings and death phantoms are actually the same species. The larvae of underdark helicopter damselflies larvae can metamorphose into adulthood from a range of instars (larval growth stages) far wider than any natural odonatid, with adult sizes ranging from a Small ghostwing to a Huge death phantom. To eradicate the mammoth underdark damselflies would thus require slaying every ghostwing in the Underdark and destroying all their eggs and naiads. The drow are unaware of this, and the task is nearly impossible even if they knew.
 After mating, female underdark helicopter damselflies lay their eggs in water to hatch into the next generation of naiads, which become adults when environmental cues trigger their transformation. In general, naiads who live alongside larger predators transform into adulthood as early as possible, becoming ghostwings and flying to somewhere safer, explains why the underdark giant damsels' commonest adult size is the ghostwing. However, the most successful naiads will grow into one of these "larger predators" themselves before becoming old enough to metamorphose into adults, in which case they attempt to reach Huge size and become death phantoms.
 Underdark helicopter damselfly naiads can become intermediary adults between a ghostwing and death phantom in size, but this is unusual. This typically only happens when their water pool is just big enough for a single naiad to develop into a Large underdark helicopter damselfly, a creature dubbed a Wraithwing by the surface dweller who discovered it (see Imperial Giant Dragonfly for statistics).
 An underdark damselfly's eggs can survive out of water for an impressive length of time, lying dry and dormant until conditions are better. In addition, underdark damselfly naiads are incredibly adaptable, able to live in an extremely wide range of water temperature and chemistry, from near-boiling brine to crystal-clear icewater, and are also amphibious, able to breathe air as well as water. While they prefer to live in water, an underdark damselfly naiad only has to be submerged when it hatches from its egg, or when a naiad of Large size or bigger needs to molt its exoskeleton and grow into its next instar (see Mammoth Damselfly Naiad for details).
 Tied to Eldritch Depths. Underdark helicopter damselflies have become dependent on the Underdark's mystic radiations. Without regular exposure to its eldritch glow they wither and perish in weeks, which becomes days if they contact the light of the surface world. Daylight or moonlight will cause the corpse to rapidly decompose into useless waste, much like how some drow equipment cannot abide the touch of the sun.

(Monster designed by Casimir Liber and Cleon on Enworld.org's General Monster Talk Creature Catalog Forum; inspired by the tropical giant dragonfly that debuted in EX2 The Land Beyond the Magic Mirror (1983) by Gary Gygax.)

 

[Cleon]

Odonatid, Giant (Mammoth Damselfly Naiad)
Huge beast, unaligned
Armor Class 15 (natural armor)
Hit Points 76 (8d12 + 24)
Speed 30 ft., swim 30 ft.

STR​	DEX​	CON​	INT​	WIS​	CHA​
22 (+6)​	14 (+2)​	17 (+3)​	1 (–5)​	12 (+1)​	5 (–2)​

Skills Stealth +6
Senses blindsight 30 ft., passive Perception 11
Languages —
Challenge 4 (1,100 XP) Proficiency Bonus +2

Ambusher. In the first round of a combat, the giant odonatid has advantage on attack rolls against any creature it surprised.

Actions

Bite. Melee Weapon Attack: +8 to hit, reach 5 ft., one target. Hit: 19 (3d8 + 6) slashing damage and the target is grappled (escape DC 16). Until this grapple ends, the target is restrained, and the giant odonatid can't bite another target.

Death Mask (Recharge 4–6). Melee Weapon Attack: +8 to hit, reach 10 ft., one target. Hit: 19 (3d8 + 6) piercing damage. If the target is a Gargantuan or smaller creature, the target is grappled (escape DC 16) and must make a DC 16 Strength saving throw. On a failure, the target is knocked prone, and the giant odonatid can drag the target closer and make one bite attack against it as a bonus action. Until this grapple ends, the odonatid cannot use its Death Mask attack again.


Description

A mammoth damselfly naiad tends to be brown in color and somewhat flattened, but resembles a standard damselfly naiad (see Giant Damselfly Naiad for details). They are much bigger, with fully grown naiads being roughly 18 feet long.

VARIANT: MAMMOTH TROPICAL DRAGONFLY NYMPH
This is the larva of a Huge giant dragonfly, usually a tropical species (see Mammoth Helicopter Damselfly for details). A mammoth tropical dragonfly nymph is 12 to 15 feet in length and uses a mammoth damselfly naiad's statistics, except it is slower (30 ft., swim 10 ft.) and gains the following action option.
 Jet Dash (Recharge 5–6). The dragonfly nymph swims up to 80 feet.

VARIANT: MAMMOTH TENEBROUS & UNDERDARK DAMSELFLY NAIADS
These are larvae of monstrous damselflies adapted to live in dark environments (see Mammoth Helicopter Damselfly for details, under Tenebrous Helicopter Damselflies and Underdark Helicopter Damselflies). A mammoth tenebrous damselfly naiad has blindsight 30 ft. and darkvision 90 ft.
 
A mammoth underdark damselfly naiad, also known as death phantom naiad, has a challenge rating of 5 (1,800 XP) and uses a mammoth damselfly naiad's statistics, except it moves as well on land as water (30 ft., climb 30 ft., swim 30 ft.), has Stealth +5, blindsight 60 ft. and darkvision 120 ft., its bite and death mask attacks have +9 to hit and escape DC 17, and it gains the following additional traits and action option.
 Amphibious. The death phantom naiad can breathe air and water.
 Magic Resistance. The death phantom damselfly has advantage on saving throws against spells and other magical effects.
 Shimmer of Imperceptibility. The death phantom naiad vibrates its wing-buds to create a strange shimmering. Any creature that sees it must succeed on a DC 13 Wisdom saving throw or be charmed until the wing-buds' vibration ends. If a creature has Fey Ancestry and sees the Shimmer of Imperceptibility with darkvision, the trait does not give the creature advantage on saving throws against being charmed by the shimmer. The death phantom naiad must take a bonus action on its subsequent turns to continue the shimmering. It can stop the shimmering at any time. The shimmering ends if the death phantom naiad is incapacitated or moves more than 10 feet on its turn.
 While charmed by the shimmer, a creature becomes unable to perceive the death phantom naiad with any form of sight apart from truesight, so the naiad becomes invisible to the creature, even to blindsight and the see invisibility spell. Unlike a normal charm, the charmed creature can still attack the death phantom or target the naiad with harmful abilities or magical effects, and the naiad does not gain advantage on social interaction ability checks with the creature.
 The hypnosis effect ends if the target takes any damage from the death phantom naiad. If a charmed creature takes damage from a source other than the death phantom or is about to face another obvious danger, such as an approaching fire, it can repeat the saving throw. A charmed creature can also repeat the saving throw if it takes an action to try to see the death phantom naiad, but if the naiad is trying to hide the creature must first succeed at a Perception check against the naiad's Stealth check to be allowed the attempt. If the saving throw is successful, the effect ends on it. A creature that successfully saves is able to resist the shimmer for the next 24 hours. If the creature fails a saving throw during their period of resistance against the death phantom naiad's Shimmer of Imperceptibility, it is only partially charmed and merely has trouble seeing the insect, with the same effect as the blur spell (the partially charmed creature has disadvantage to attack the naiad, the naiad does not gain advantage on its attacks).

VARIANT: MAMMOTH TERRESTRIAL DAMSELFLY & DRAGONFLY LARVAE
This is a mammoth damselfly naiad or mammoth dragonfly nymph adapted to live on land, although It cannot survive dry conditions for long (see Giant Dragonfly Nymph for details, under Terrestrial Giant Odonatid Larvae). A mammoth terrestrial odonatid larva uses a mammoth damselfly naiad's statistics, except it moves better on land than water (30 ft., climb 20 ft., swim 10 ft.), loses the Jet Dash action option if it's a dragonfly nymph, and gains the following additional trait.
 Limited Amphibiousness. The terrestrial odonatid larva can breathe air and water, but it needs to be drenched in water at least once every 4 hours to avoid suffocating.

(Monster designed by Casimir Liber and Cleon on Enworld.org's General Monster Talk Creature Catalog Forum; inspired by the tropical giant dragonfly nymph that debuted in EX2 The Land Beyond the Magic Mirror (1983) by Gary Gygax.)

 

[Cleon]

Odonatid, Giant (Giant Helicopter Damselfly)
Huge beast, unaligned
placeholder
(Original monster designed by Casimir Liber and Cleon on the Creature Catalog Monster Homebrews forum)

Been dithering about what to call these, as "Helicopter Damselfly" sounds a bit odd for D&D unless tinker gnome flying machines are common in the campaign!

Maybe Giant Tropical Damselfly as a call-back to AD&D having tropical giant dragonflies be stronger versions of giant dragonflies?

Heck, let's use that.

 

[Casimir Liber]

Ok so starting with a huge CR 3 Giant Tropical Damselfly...?

 

[Cleon]

Ok so starting with a huge CR 3 Giant Tropical Damselfly...?

The Giant Tropical Damselfly has some unusual behaviour compared to a regular Odonatid, so I'm inclined to start with the Giant Dragonfly and basically scale it up and down from there for the others.

As for Challenge Rating, I'm thinking the Nymphs will have roughly the same CR as the Adults (Odonatid naiads are vicious little devils) and obviously they'd go up in CR as they scale up in size, but haven't decided whether the Emperor Dragonfly is a better candidate for Challenge 3 or the Giant Tropical Damselfly.

It really depends on what we want them to be tough enough to eat. If the Emperor routinely catches Giant Horseflies for example, logically it would need a significantly higher Challenge than the Tabanid's CR 1 and might be CR 3 itself. If it maxes out at CR 1/2 prey like Giant Wasps I could see it as having CR 2 or so.

Also, it's literally Huge! That's the size of an Elephant. Methinks Challenge 3 is pretty much a minimum for a Giant Tropical Damselfly, and I think it works better a bit higher.

For comparison, the Huge Beasts in the Monster Manual are:

Dinosaur, Ankylosaurus—CR 3
Dinosaur, Triceratops—CR 5
Dinosaur, Tyrannosaurus rex—CR 8
Elephant—CR 4
Giant Ape—CR 7
Giant Constrictor Snake—CR 2
Giant Crocodile—CR 5
Giant Elk—CR 2
Giant Shark—CR 5
Killer Whale—CR 3 [that's a bit low!]
Mammoth—CR 6
​

Now I think it makes more sense thinking of a Giant Tropical Damselfly as being like a giant crocodile or giant shark that can fly, so somewhere around Challenge 5 or 6 feels about right.

The rest of the Challenge Ratings can just scale down from there.

How about these targets:

Giant Damselfly—CR 1 [or maybe CR 1/2?]
Giant Dragonfly—CR 2 [or maybe CR 1?]
Giant Emperor Dragonfly—CR 3
Giant Tropical Damselfly—CR 5
​

The reason I'm putting the Giant Dragonfly at Challenge 2 rather than 1 is that the AD&D versions are fairly close in lethality, so a 50% jump in CR is a better match than a 100% one.

Further thought, and I'm liking the Damselfly as being Medium sized but weaker than a Dragonfly, so will change the Small nymph to a generic Odonatid. Damselfly larva are just as lethal as dragonfly larva.

EDIT: Okay, I've updated the Index of 5E Monster Arthropods with some proposed target Challenge Ratings for the Odonata.

 

[Cleon]

Okay, let's get this show on the road.

I think the Giant Dragonfly should be on the upper range of lethality for a Medium beast, since the original monster was exceptionally nasty for a M sized animal. Its AC and HD were considerably higher than an AD&D Lion!

Although Lion's made up for that by being living cuisinarts in early editions of D&D, due to them having up to five attacks.

Still, the Monstrous Compendium Giant Dragonfly was XP 1,400 (2,000 for tropical) to a Lion's XP 650, which is further justification for making them Challenge 2.

The AD&D Lion's basic attacks (1d4/1d4/1d10=10½) are a bit more damaging than the basic Giant Dragonfly (3d4=7½) but comparable to a Tropical Giant Dragonfly (4d4=10) and it's less accurate (THAC0 15 vs THAC0 13, so one step lower in the AD&D combat progression).

The Lion's Hit Points are lower (5+2 HD=24½) vs (7 HD=31½) for the Dragonfly.

Its Armour Class is also worse (AC 5/6 vs AC 3, so 2 or 3 points lower).

Methinks the best way of interpreting that is giving the Dragonfly a superhigh Dexterity so its AC and melee attacks are better than a Lion, which uses its STR +3 and DEX +2 modifiers for those derived stats. Probably DEX +4?

 

[Cleon]

I started writing up a rough and ended up basically statting up the whole thing.

It needs damage figures for its attacks and I might need to tweak the Hit Points to make it Challenge 2, but it's good enough to put in the Giant Dragonfly Working Draft.

So I will!

Odonatid, Giant (Giant Dragonfly)
Medium beast, unaligned
Armor Class 15 (natural armor)
Hit Points 38 (7d8 + 7)
Speed 10 ft., fly 60 ft.

STR​	DEX​	CON​	INT​	WIS​	CHA​
14 (+2)​	18 (+4)​	13 (+1)​	1 (–5)​	12 (+1)​	## (+–#)​

Saving Throws DEX +6
Senses passive Perception 11
Languages —
Challenge 2 (450 XP) Proficiency Bonus +2

Evasive Flight. A giant odonatid gains advantage on Dexterity saving throws when flying and attackers have disadvantage on attack rolls against it.
 If the giant odonatid is mounted or grappling an opponent, it must make a DC 12 STR check to use evasive flight each time it is attacked.

Flyby. The giant odonatid doesn't provoke opportunity attacks when it flies out of an enemy's reach.

Keen Sight. The giant odonatid has advantage on Wisdom (Perception) checks that rely on sight.

Actions

Multiattack. The giant odonatid makes two attacks against a Small or smaller creature it is not grappling. The first attack is a legs attack. If this succeeds in grappling the target, the odonatid makes a bite attack, otherwise it makes a second legs attack.

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: # (#d# + 4) slashing damage.

Legs. Melee Weapon Attack: +# to hit, reach 5 ft., one target. Hit: # (#d# + #) bludgeoning damage, and the target is grappled (escape DC 12). Until this grapple ends, the target is restrained, and the giant odonatid can't make legs attacks against another target.

Reactions

Dodging Flight. If a creature of at least Small size attempts a melee attack against a giant odonatid, or the insect is targeted by a ranged weapon of similar size such as a giant-hurled boulder, the giant odonatid can try to dodge out of the way as a reaction. The giant odonatid makes a Dexterity saving throw with advantage (it loses this advantage when mounted or grappling an opponent. If the saving throw beats the attack roll or DC of the attack the giant odonatid takes no damage and flies up to 30 feet.
 If a giant odonatid is grappling a creature when it uses Dodging Flight, flying, the creature can make an escape check as a free action. If it fails, the odonatid flies away with its victim.


Description

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(Originally appeared in EX2 The Land Beyond the Magic Mirror (1983) by Gary Gygax.)

 

[Cleon]

Dang it, forgot the Charisma. Think I'll give it CHA 5 to make them slightly more attractive than a Giant Spider, since D&D seems to like picking the fugliest spiders to represent the monstrous version but the flavour text of the Giant Dragonflies suggests they are quite attractive.

You probably note that most of its special abilities are cribbed from the Giant Horsefly. There seemed little point in reinventing the wheel and the Tabanid's Evasive Flight and Dodging Flight where an ideal match for the defensive abilities of the AD&D Giant Dragonfly.

I did notice an error in the Giant Tabanid while transcribing them. It should have Keen Sight not Vision.

Will amend the Enworld version and leave it up to you whether to bother doing the same with the D&D Beyond Giant Tabanid incarnation.

 

[Cleon]

Double dang it, it's missing (hover) after it's fly speed. I was sure I'd already included that.