5E: Monstrous Arthropods for Fifth Edition

[Cleon]

Okay, I crunched some numbers and due to its numerous special abilities I had couldn't get getting a Medium beast Giant Dragonfly to fit into 7 HD and Challenge 2 without giving it piddling damage.

Also, if I had its Legs do bludgeoning damage it boosted the CR too high except for the Giant Tropical Damselfly.

So I came up with the following:

Creature​	Challenge​	Hit Points​	STR​	DEX​	CON​	Attacks​	Escape​
Damselfly	1 (200 XP)​	18 (4d8)​	12 (+1)​	18 (+4)​	11 (+0)​	Bite +6 to hit, 6 (1d4 + 4)	DC 11​
Dragonfly	2 (450 XP)​	27 (5d8 + 5)​	14 (+2)​	18 (+4)​	13 (+1)​	Bite +6 to hit, 8 (1d8 + 4)	DC 12​
Emperor	3 (700 XP)​	45 (7d10 + 7)​	18 (+4)​	18 (+4)​	13 (+1)​	Bite +6 to hit, 11 (2d6 + 4)	DC 14​
Tropical	5 (1,800 XP)​	68 (8d12 + 16)​	20 (+5)​	18 (+4)​	15 (+2)​	Bite +8 to hit, 18 (3d8 + 5) Legs +8 to hit, 8 (1d6 + 5)	DC 16​

Those seem about right.

Will update the Giant Dragonfly Working Draft.

 

[Casimir Liber]

Giant Tabanid corrected

the dragonflies statted out thus far look good and am happy with adding flying reactions etc.

 

[Cleon]

Giant Tabanid corrected

Have updated the Indexes.

…hold on a second, where's the Credit!

For some reason, I gave it:

(Monster designed by Casimir Liber and Cleon on the Creature Catalog Monster Homebrews forum)
​

But the Giant Horsefly is originally a 1E AD&D monster, so it should refer to the first published source to b econsistent with our other conversions.

That means it should have:

(Originally appeared in Monster Manual II (1983) by Gary Gygax.)
​

I'll update the Giant Horsefly with that.

the dragonflies statted out thus far look good and am happy with adding flying reactions etc.

I'll go put the numbers in the other Odonatids then.

Updating the Giant Damselfly.
Updating the Giant Dragonfly.
Updating the Giant Emperor Dragonfly.
Updating the Giant Tropical Damselfly.

 

[Cleon]

I did wonder about tweaking the ability scores slightly, like so:

Creature​	STR​	DEX​	CON​
Giant Damselfly	12 (+1)​	18 (+4)​	11 (+0)​
Giant Dragonfly	15 (+2)​	18 (+4)​	12 (+1)​
Giant Emperor Dragonfly	18 (+4)​	18 (+4)​	13 (+1)​
Giant Tropical Damselfly	21 (+5)​	18 (+4)​	14 (+2)​

Just so the progression is more even.

It doesn't change the modifiers so none of the derived stats will change.

I also toyed with the idea of giving the Damselfly a Strength with a +0 modifier so its Legs have (escape DC 10) and it has a significantly lower chance of dodging while carrying a victim.

Also wondered about not giving it any natural armour so it has Armor Class 14.

Similarly, I wondered about giving the Tropical Giant Damselfly DEX 17 and CON 14 instead of the current DEX 18 and CON 15 so it has the same Saving Throw as the other Odonatids.

In the end the latter two ideas didn't seem desirable, but I am getting tempted by the ability score tweaks in the table above.

What do you think?

 

[Cleon]

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 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.

The second paragraph of Dodging Flight still needs work.

How about:

 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.
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That's a lot better. Will update the Working Drafts.

 

[Cleon]

So any objection to this?

I did wonder about tweaking the ability scores slightly, like so:

Creature​	STR​	DEX​	CON​
Giant Damselfly	12 (+1)​	18 (+4)​	11 (+0)​
Giant Dragonfly	15 (+2)​	18 (+4)​	12 (+1)​
Giant Emperor Dragonfly	18 (+4)​	18 (+4)​	13 (+1)​
Giant Tropical Damselfly	21 (+5)​	18 (+4)​	14 (+2)​

Just so the progression is more even.

It doesn't change the modifiers so none of the derived stats will change.

If not, I'll update the Odonatids' abilities in a day or two.

 

[Cleon]

Hmm, the original AD&D Giant Dragonfly could only grapple Tiny creatures with its leg basket, so I've wondering about reducing the grapple limit of the Odonatids a bit.

However, I want the Giant Emperor Dragonfly to be able to catch Giant Wasps, which are Medium size.

We could make it so the Medium sized Odonatids can only catch Tiny prey with its legs.

Or maybe have it so the Multiattack is limited to a smaller size than its Legs? So it could grab a Small creature with a Legs attack on its first turn and then Bite on its second turn, but it can grapple and bite a Tiny creature on the same turn with Multiattack?

That'd work, and it would explain why they normally only grapple much smaller prey.

 

[Cleon]

I'm also wondering about giving it an ability to counteract a flying target's ability to dodge out of the way, since Odonata specialize in catching flying insects that naturally would rather not be caught and eaten.

How about one of the following:

Aerial Dogfighter #1. If a giant odonatid is flying and attacks a creature with Dodging Flight, Evasive Flight or a similar defensive ability, the target must have a DEX saving throw modifier higher than the odonatid's DEX +6 save to use the defense.

Aerial Dogfighter #2. If a giant odonatid is flying and attacks a creature with Dodging Flight, Evasive Flight or a similar defensive ability, the target must make a DC 16 Dexterity saving throw to use the defense.

Motion Camouflage. The giant odonatid selects a creature and flies towards it. The creature must succeed at 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.
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Of the above, I like Motion Camouflage the best.

Incidentally, Motion Camouflage (see Wikipedia) is a real thing.

I have no idea how many species of dragonfly use motion camouflage. The Australian Emperor Anax papuensis definitely does (there's a paper in Nature), but it was observed using it in male-to-male fights rather than prey capture.

Still, a little thing like a lack of rigorous scientific proof doesn't stop us giving it to a D&D Monster.

Apart from its unnatural size, the D&D Giant Dragonfly has significant behavioural differences to a natural dragonfly. It attacks creatures on the ground for a start, and will make hit-and-run bite attacks against targets as big or bigger than it is. Neither of those are things real dragonflies do.

 

[Cleon]

Motion Camouflage. The giant odonatid selects a creature and flies towards it. The creature must succeed at 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.

Hmm, should I give the Dragonfly proficiency or advantage on Acrobatics checks when flying?

Something like:

Expert Aerialist. The giant odonatid has advantage on Dexterity (Acrobatics) checks when flying.
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It's very tempting, but might be gilding the lily.

If the SRD Panther doesn't get Acrobatics proficiency the Dragonfly might have to make do with its default of DEX +4.

You know, the 5E big cats are really quite feeble compared to their AD&D and 3E incarnations.

They don't even grapple creatures with their claws. That's what they're for!

If I ever have too much time on my hands, I might do some Panthera in the 5E: Alternate Takes on Official Fifth Edition Monsters thread.

 

[Casimir Liber]

So any objection to this?



If not, I'll update the Odonatids' abilities in a day or two.

No, all these look fine

Happy with Motion Camouflage

I strongly support giving them acrobatics and also support some Big Cats with Teeth (i.e. alternate takes)