OK, here are some summaries of the creatures we came up with in this thread, as well as a few more.

It took us some time to put this together, as you might imagine.
Now would be the time to weed out the ones we definitely don’t want, to better compare the ones we would rather consider. Things that need to go away include: creatures that would definitely be better as another type (Magical Beast, Aberration, etc), things that only have the LVT (“Lazy Vermin Trick”, aka poison) and not much else going for them, things that are just too similar to something already in the game, anything that would not be worthwhile to convert into modern game mechanics, and anything that’s flat out not interesting.
That should, hopefully, leave us with the more interesting, unique, and usable vermin which to submit. We'd also like to get a nice CR range, with some simple vermin, swarms, complex and intelligent creatures, with a wide variety of abilities.
If you need more information on any of these to make a better judgment, just say so.

Likewise, if you know of something in the creature’s original description that bears mentioning, let us know as well.
Addazahr ("backbiters")
Size: T
HD: 1 hp
Attacks: Bite
SA: Disease
SQ: None
Int: Mindless
Environment: Tropical, subtropical, and temperate desert hills, plains
Organization: 6-60 (swarm)
Sources: Corsairs of the Great Sea, MCA2
Notes: Would probably be best as a swarm
Giant Amoeba
Size: H
HD: 10-15
Attacks: Acidic touch
SA: Acid, envelop
SQ: X
Int: Mindless
Environment: ?
Organization: Solitary
Sources: X2, AC9, DMR2
Notes: Possibly an ooze instead
Giant Anemone
Size: L
HD: 16
Attacks: 1d3 groups of 1d10 tentacles per round
SA: Poison, paralysis, swallow whole, spew acid
SQ: Regeneration
Int: Mindless
Environment: Temperate and warm saltwater
Organization: School (3-18)
Sources: MC4
Notes:
Giant Sea Anenome
Size: L
HD: 7
Attacks: 1-3 tentacles
SA: Paralytic poison, entrapment, swallow prey whole, continuous damage
SQ: -
Int: Mindless
Environment: Oceans
Organization: 1 or 50-200
Sources: Dragon #116
Notes:
Driver Ant
Size: D
HD: 4
Attacks: Bite
SA: None
SQ: None
Int: Mindless?
Environment: ?
Organization: 2-8
Sources: D&D Basic Rules (1981)
Notes:
Antloid, Desert = another case of various varieties of different creature types (some have psionic powers, for example). (MC 12)
Aratha (Killer Beetle)
Size: L
HD: 9
Attacks: 4 clawed tentacles (20’ reach)
SA: Psionics, improved grab
SQ: Tremorsense, immunity to fire and petrification
Int: Average (8-10)
Environment: Temperate land (non-mountainous)
Organization: Solitary
Sources: Dragon 89, Ruins of Myth Drannor, MCA1
Notes: beetle with large purple-to-brown carapace
Aspis: these could be Vermin, Monstrous Humanoids, Aberrations, or more than one type.
Sources: A1, MM2, MC5
Assassin Bug
Size: T
HD: 1
Attacks: Bite
SA: Anesthetic, egg implantation
SQ: None
Int: Mindless
Environment: ?
Organization: Mated Pair
Sources: FF
Notes:
Killer Bee
Size: T
HD: 1/2
Attacks: Sting
SA: LVT, wounding stinger
SQ: None
Int: Mindless?
Environment: ?
Organization: 1-6
Sources: D&D Basic Rules (1981)
Notes:
Beetle, Agony
Size: F
HD: 1+5
Attacks: Tendril
SA: Spinal tap, psionic drain, anesthetic tendril
SQ: None
Int: Mindless
Environment: Any
Organization: 1-4
Sources: MC12
Notes:
Boring Beetle
Size: L
HD: 5
Attacks: Bite
SA: None
SQ: Hive Mind
Int: Mindless
Environment: Any land
Organization: 3-18
Sources: MM, MC2, MonMan
Notes:
Dragon Beetle
Size: T
HD: 1
Attacks: Bite or stinger
SA: Dragonbane venom, swarmfighting
SQ: None
Int: Mindless
Environment: Desert and underground
Organization: Nest (2-6 plus leader)
Sources: City By the Silt Sea, MCA2
Notes:
Earthquake Beetle
Size: C
HD: 40
Attacks: 4 Slams/Bite
SA: Earthquake from burrowing, acid breath weapon
SQ: None
Int: 2
Environment: ?
Organization: Solitary
Sources: DMR2
Notes: orange-red beetle with 10 legs and the head of a black dragon
Giant Oil Beetle
Size: S
HD: 2
Attacks: Bite
SA: Oil
SQ: None
Int: Mindless
Environment: Warm land and underground
Organization: Solitary, (1-8) or (2-12)
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia (1991)
Notes:
Rhinoceros Beetle
Size: L
HD: 12
Attacks: Bite, Horn
SA: None
SQ: None
Int: Mindless
Environment: Any jungle
Organization: 1-6
Sources: MM, MC2, MonMan
Notes:
Slicer Beetle
Size: L
HD: 6
Attacks: Bite
SA: Vorpal bite (on a critical hit, severs limb)
SQ: None
Int: Mindless
Environment: Forest
Organization: 1-3
Sources: MM2, MC5
Notes:
Beetle, Stink
Size: S
HD: 3+1
Attacks: Bite
SA: Stink
SQ: None
Int: Mindless
Environment: Temperate forest
Organization: 1-3
Sources: MCA3 (probably not original source)
Notes: Looks like slicer beetle.
Giant Tiger Beetle
Size: S
HD: 3
Attacks: Bite
SA: None
SQ: None
Int: Mindless
Environment: ?
Organization: 1-6
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia (1991)
Notes: has a striped carapace that looks like a tiger’s skin
Water Beetle
Size: M
HD: 4
Attacks: Bite
SA: None
SQ: Hold Breath
Int: Mindless
Environment: Fresh water
Organization: 1-12
Sources: MM, MC2, MonMan
Notes:
Giant Bloodworm
Size: H
HD: 6
Attacks: Bite
SA: Attach, Blood drain
SQ: None
Int: Mindless
Environment: Underground/Aquatic
Organization: 1-4
Sources: FF
Notes:
Bookworm: might want to pitch as a hazard
Sources: MM2, MC1, MonMan
Burbur
Size: T
HD: 1-2
Attacks: Bite (affects slimes, mosses, molds only)
SA: Stink
SQ: Immunities (to slimes, mosses, and molds' abilities)
Int: Mindless
Environment: Any land
Organization: 1-4
Sources: Dragon 101, MC3, MCA3
Notes: Useful "pet" since it eats what it is immune to.
Buzzjewel
Size: T
HD: 1+1
Attacks: Bite
SA: Poison
SQ: Spell reflection
Int: Mindless
Environment: Wildspace
Organization: Swarm (10-60)
Sources: MC9
Notes: Will probably need to be adapted beyond space. This may work better as a swarm.
Caecillia
Size: G
HD: 6
Attacks: Bite
SA: Swallow whole
SQ: -
Int: Mindless
Environment: Any non-arctic
Organization: Solitary
Sources: D&D Expert Set, Rules Cyclopedia, Mystara MC
Notes: giant worm-like creature
Carrion Stalker
Size: T
HD: 4
Attacks: 8 stinging tendrils
SA: Entangle, spawning
SQ: Hide in corpse
Int: Mindless
Environment: Subterranean
Organization: 1d6
Sources: RL MCIII
Notes:
Cave Cricket
Size: S
HD: 1
Attacks: ---
SA: Jump-kick (1d4 dam)
SQ: Chirp (drowns out noise, draws monsters)
Int: Mindless
Environment: ?
Organization: 1-8
Sources: S4, MM2
Notes:
Cave Moray
Size: M
HD: 4
Attacks: 2-8
SA: Attack from surprise
SQ: Withdraw into cyst-burrows
Int: Mindless
Environment: ?
Organization: 4-16
Sources: S4, MM2
Notes: Slug-like
Giant Clam
EX2 (don’t have access to that module at the moment)
Giant Clam (Oyster)
Size: M
HD: 3+3
Attacks: "Bite"
SA: Entrapment, sever limbs
SQ: -
Int: Mindless
Environment: Ocean shallows
Organization: 1-4
Sources: Dragon #116, MCA4
Notes:
Giant Clam
Size: M
HD: 3
Attacks: -
SA: -
SQ: -
Int: Mindless
Environment: Shallow tropical and semitropical waters
Organization: 1-4
Sources: Dragon #116
Notes:
Giant Carnivorous Clam
Size: M
HD: 4
Attacks: 1 ram
SA: Neurotoxin cloud
SQ: -
Int: Mindless
Environment: Shallow tropical and semitropical waters
Organization: 1-4
Sources: Dragon #116
Notes:
Coral Worm
Size: L to H
HD: 3-8
Attacks: Bite
SA: Razor edges
SQ: Retreat into coral tube
Int: Mindless
Environment: Deep coastal
Organization: Colony (10-100)
Sources: LNA2 Newhon, MCA4
Notes:
Giant/Monstrous Crayfish
Size: L
HD: 4
Attacks: 2 claws
SA: None
SQ: Surprise
Int: Mindless
Environment: Temperate freshwater rivers
Organization: 1-4
Sources: MM, MC2, MonMan
Notes:
Dragonfly (white/black/green/blue/red)
Size: S
HD: 3/3+2/4/4+2/5
Attacks: Bite
SA: Breath weapon
SQ: -
Int: Mindless
Environment: Varies
Organization: 3d6
Sources: XL1, DMR2, Mystara MC
Notes: Dragons mixed with insects. Entry also has stats for nymph stage, which are indistinguishable until maturity (all have acid breath weapon).
Giant Dragonfly (plus larva/nymph stage)
Size: M
HD: 7
Attacks: Bite
SA: Initiative bonus
SQ: Saves bonus
Int: Low (5-7) (or Mindless per MC5)
Environment: Warm & temperate forest & marsh
Organization: 1-6
Sources: MM2, MC5
Notes: Hunt humans
Dreamweaver
Size: T
HD: 1+1
Attacks: Bite
SA: Poison
SQ: DR/magic, vulnerable to sunlight
Int: Low (7)
Environment: The Nightmare Lands
Organization: Swarm (3-18)
Sources: The Nightmare Lands, MCA3
Notes: Probably a swarm. "Weaves dreams and nightmares".
Ear Seeker
Size: T
HD: 1/2 (1 hp)
Attacks: -
SA: Burrowing larva (deal 1d4 dmg/round)
SQ: vulnerable to cure disease
Int: Mindless
Environment: Any land
Organization: 1d4
Sources: MM, City of Delights, MCA1
Notes: Parasite
Fal = As magical, genius-level intelligent beings, they are probably outside the scope of this query.
Feesu
Size: S
HD: 2+2
Attacks: Bite
SA: Air deprivation, feed on light, shed light
SQ: Immune to blunt weapons, vulnerable to edged weapons and fire
Int: Mindless
Environment: Wildspace
Organization: Swarm (6-48)
Sources: MC9
Notes: Will probably need to be adapted beyond space. This may work better as a swarm.
Fireball Fly
Size: F
HD: 1 hp
Attacks: Bite
SA: Fireball burst
SQ: Immune to fire, destroyed by cold
Int: Mindless
Environment: "rocky areas" and underground
Organization: 2-12 (6-36 in lair)
Sources: Dragon #94
Notes: Could be a swarm.
Flail Snail
Size: L
HD: 4
Attacks: 1 club-tentacle per HD
SA: None
SQ: Immunity to fire, poison; shell acts as robe of scintillating colors; blindsight
Int: Low (5-7)
Environment: Underground
Organization: Solitary
Sources: FF, MC5
Notes: Possibly an Aberration
Flawder
Size: S
HD: 1-3
Attacks: By weapon
SA: None
SQ: None
Int: Average (8-10)
Environment: Temperate and warm aquatic
Organization: Tribe (4-80)
Sources: MC14
Notes: Snail-like tentacled nomad; may not be a good candidate for vermin.
Fleas of Madness
Size: F
HD: N/A
Attacks: N/A
SA: Madness
SQ: -
Int: Mindless
Environment: Temperate or tropical lands
Organization: Infestation (hundreds)
Sources: RL MCIII
Notes: This is essentially either a hazard or a swarm.
Giant Fly (Bluebottle/Horsefly)
Size: M/L
HD: 3/6
Attacks: Bite
SA: Disease/Blood Drain
SQ: Jump
Int: Mindless
Environment: ?
Organization: 1-10/1-4
Sources: MM2
Notes:
Fyrefly on the CC we decided would be a Magical Beast, though of course there is always the possibility for reconsideration…
Fyrsnaca
Size: G
HD: 10
Attacks: Bite
SA: Fiery breath, spawn red worms
SQ: -
Int: Low (5-7)
Environment: Subterranean
Organization: 1-2
Sources: AC9, DMR2, Mystara MC
Notes: giant firey snake-worm
Gloomwing
Size: M
HD: 5
Attacks: Claw/Claw/Bite
SA: Pheromones cause Str damage, Snatch
SQ: Coloration causes confusion
Int: Mindless
Environment: Demiplane of Shadow
Organization: Solitary
Sources: MM2, MC11, MonMan
Notes: Moth
Tenebrous Worm
Size: M
HD: 10
Attacks: Bite
SA: Acid bite
SQ: Poison bristles (paralysis/death)
Int: Mindless
Environment: Demiplane of Shadow
Organization: Solitary
Sources: MM2, MC2, MonMan
Notes: Larval form of gloomwing
Goldbug
Size: T
HD: 1
Attacks: Bite
SA: Blood drain, poison
SQ: Disguise, vulnerable to cure disease
Int: Mindless
Environment: Any land
Organization: 1d20
Sources: FF, City of Delights, MCA1
Notes: Parasite that looks like a gold piece.
Gossamer (Standard/Noble)
Size: T/C
HD: 1 hp/58 HD
Attacks: Sting/20 stings
SA: Poison stinger
SQ: Death throes
Int: Mindless/Animal (2-4)
Environment: Space/Wildspace, phlogiston
Organization: Shoal (20-200)/flotilla (1-8)
Sources: MC9
Notes: Will probably need to be adapted beyond space.
Great Annelid
Size: C
HD: 25-50
Attacks: Bite
SA: Swallow whole, attract and paralyze earth elementals
SQ: Immune to heat and pressure
Int: Mindless
Environment: Subterranean
Organization: Solitary
Sources: DMR2, Mystara MC
Notes: immense worm creature
Greelox
Size: L
HD: 6+12
Attacks: 2 legs/2 arms/bite or wields weapons
SA: Poison, acidic webs, shadow magic
SQ: +2 or better DR, hide in shadows, immunity to poison and acid,
shadow jump
Int: High (13-14)
Environment: Any underground/ruins or Plane of Shadow
Organization: 1
Sources: Dungeon 35, MCA1
Notes: Probably a magical beast, not vermin.
Hallucigenia
Size: H
HD: 9
Attacks: Tail slap & 6 tentacles
SA: Constrict, improved grab, piercing trample
SQ: Water dependent
Int: Mindless
Environment: Any aquatic
Organization: Solitary or cluster (2-4)
Sources: Dragon 204
Notes: bizarre, primitive life-form
Acidic Hallucigenia
Size: L
HD: 5
Attacks: 6 spines & 7 tentacles
SA: Acid jet
SQ: Immunity to acid
Int: Mindless
Environment: Any land and underground
Organization: Solitary or pair
Sources: Dragon 204
Notes: bizarre, primitive life-form
Cave Hallucigenia
Size: S
HD: 4
Attacks: Spine slam
SA: Attach, blood drain, yank upward
SQ: None
Int: Mindless
Environment: Underground
Organization: Solitary or colony (1-12)
Sources: Dragon 204
Notes: bizarre, primitive life-form
Haun
Size: S
HD: 1/2
Attacks: Bite
SA: Psionics, SLAs, leap
SQ: None
Int: Exceptional (15-16)
Environment: Arctic ice pack and glaciers
Organization: 2-5
Sources: MC11
Notes: C(E) in alignment, ice worm, parasite of haundars
Haundar
Size: H
HD: 20
Attacks: Bite
SA: Spit acid
SQ: Scent
Int: Mindless
Environment: Icebergs, arctic valleys
Organization: Solitary
Sources: MC11
Notes: ice-slug, can fly
Head Hunter
Size: T
HD: 5+5
Attacks: bite
SA: "Animate" corpse, poison, limb-severing webs, spit venom
SQ: Spell resistance, tremorsense, vulnerable to fire
Int: Average (8-10)
Environment: Ravenloft
Organization: 1-3
Sources: RL MCIII
Notes: Probably more of a magical beast than vermin.
Heart Tick
Size: D
HD: 1
Attacks: Bite, 4 barbed legs
SA: Blood drain, egg laying
SQ: None
Int: Mindless
Environment: Temperate and warm urban and underground
Organization: 1-4
Sources: MCA1
Notes:
Hendar
Size: L
HD: 6
Attacks: wing/tail and bite
SA: Drowning dive
SQ: None
Int: Average (8-10)
Environment: Desolate areas (Temperate)
Organization: Solitary or 1-3
Sources: Dragon #90, MC11
Notes: N(E) in alignment, vast worm with bat wings and horse head, possibly Aberration
Herex (Larva/adult)
Size: L/H
HD: 6-12/13
Attacks: Bite/bite, sting
SA: Acid/acid, paralysis
SQ: None
Int: Mindless
Environment: Cavern/any land
Organization: 1-6/1-3
Sources: AC9, DMR2, Mystara MC
Notes: looks like a flattened beetle with an elongated abdomen
Hivebrood = These things are an article in themselves, with varying forms that would conceivably fit different creature types.
Horax
Size: M
HD: 4
Attacks: Bite
SA: Initiative bonus, crush, improved grab
SQ: Bonus to surprise, climbing, vulnerable to cold
Int: Mindless
Environment: Underground
Organization: Colony (3-30)
Sources: MC4
Notes: insectoids with large chitinous plates on their back
Horde
Size: S-H
HD: 3-21
Attacks: Bite
SA: Telekinesis
SQ: see below
Int: High (13)
Environment: Elemental Plane of Earth
Organization: 2-8 or 1d10x100
Sources: D&D Companion Set, Mystara MC
Notes: LE alignment, looks like praying mantis; collective entities comprised of multiple bodies
Giant Hornet
Size: M
HD: 5
Attacks: Sting
SA: LVT, paralysis
SQ: None
Int: Semi (2-4)
Environment: Forest or underground
Organization: Solitary
Sources: FF, MC1
Notes:
Insect Swarm: see D&D Expert Set p52 and D&D Rules Cyclopedia p187 for ideas.
Insect Swarm, Athasian (locusts)= Doesn't really differ from locust swarm in MM3.5. (MC 12)
Insect Swarm, Athasian (mini-kanks) = Simply a locust swarm with blood drain. (MC 12)
Insect Swarm, Grasshoppers and Locusts
Size: F
HD: 1 hp/20 insects
Attacks: Bite
SA: None
SQ: None
Int: Mindless
Environment: Warm forest, hills, and plains
Organization: special (20 per sq foot)
Sources: MC4, Mon Man
Notes:
Insect Swarm, Velvet Ants
Size: F
HD: special
Attacks: Bite
SA: LVT
SQ: None
Int: Mindless
Environment: Warm and temperate forest, hills, and plains
Organization: special (100 ants/sq foot)
Sources: MC4, Mon Man
Notes:
Jammer Leech
Size: S
HD: 3
Attacks: 1 armspike
SA: Leech magic, stolen spells
SQ: Spell resistance 25%, doesn't need to breathe
Int: Semi (2-4)
Environment: Any
Organization: Solitary or cluster (1-4)
Sources: MC7
Notes:
Jellyfish, Giant (Portuguese Man-o-War)
Size: S to L
HD: 1 to 4
Attacks: Sting
SA: Paralysis
SQ: Transparent
Int: Mindless
Environment: Tropical ocean
Organization: 1-10
Sources: MM, MCA2
Notes:
Giant Jellyfish (marauder, death's head, galley)
Size: L/H/L
HD: 4/6/5
Attacks: 40/24/16 tentacle stings
SA: Paralysis, surprise/poison/spit venom
SQ: -/spell resistance 10%/tremorsense
Int: Mindless
Environment: Nonarctic ocean
Organization: School (1d10/1d4/1d6)
Sources: X7, AC9, Mystara MC
Notes:
Jishin Mushi (Earthquake Beetle)
Size: L
HD: 5+4
Attacks: Bite
SA: Tremor
SQ: Scent
Int: Average (8)
Environment: Temperate forests
Organization: 4-16
Sources: MC6
Notes:
Kalin
Size: L
HD: 7
Attacks: 2 slashing limbs and bite
SA: Crushing mandibles, improved grab, drop from webline
SQ: -
Int: Semi (2-4)
Environment: Subterranean
Organization: 1-6
Sources: City by the Silt Sea, MCA2
Notes: A mix of spider and ant, sometimes trained as mounts.
Giant Leech
Size: S
HD: 1-4
Attacks: Bite
SA: Blood Drain
SQ: None
Int: Mindless
Environment: Any marsh
Organization: 4-16
Sources: MM, MC2, MonMan (alternate D&D version in Rules Cyclopedia)
Notes:
Leech, Magical
Size: F
HD: 1 hp
Attacks: n/a
SA: Magic drain, energy burst
SQ: Spell resistance
Int: Mindless
Environment: Ravenloft wetlands
Organization: 5-30
Sources: RL MCIII
Notes: This is essentially either a hazard or a swarm.
Leech, Psionic
Size: F
HD: 1 hp
Attacks: n/a
SA: Psionic drain
SQ: -
Int: Mindless
Environment: Ravenloft wetlands
Organization: 5-30
Sources: RL MCIII
Notes: This is essentially either a hazard or a swarm.
Leech Swarm
Size: F
HD: ?
Attacks: Bite
SA: Blood Drain
SQ: None
Int: Mindless
Environment: Temperate marsh
Organization: 200-500
Sources: MC2, MonMan
Notes:
Desert Leviathan
Size: C
HD: 60
Attacks: Bite
SA: Swallow whole
SQ: Tremorsense, immune to disintegration and poison, immune to all magic and psionics that don't deal damage, take half damage from all other spells and attack forms
Int: Mindless
Environment: Desert
Organization: Solitary
Sources: AC9, DMR2, Mystara MC
Notes: gigantic worm
Marine Leviathan
Size: C
HD: 70
Attacks: Bite
SA: Swallow whole, whirlpool
SQ: Darkvision, immune to disintegration and poison, immune to all magic and psionics that don't deal damage, take half damage from all other spells and attack forms
Int: Mindless
Environment: Ocean
Organization: Solitary
Sources: AC9, DMR2, Mystara MC
Notes: gigantic worm
Giant lightning bug is probably redundant with giant firefly in Arms & Equipment Guide.
Lock Lurker
Size: T
HD: 1+3
Attacks: bite or sting
SA: Paralyzing venom
SQ: partial etherealness, mimic a coin
Int: Low (5-7)
Environment: Any land or Ethereal Plane
Organization: 1
Sources: Dragon 139, FRQ1, 2E FRCS, MCA1
Notes: Probably a magical beast, not vermin.
Giant Locust (aka Cave Locust)
Size: S
HD: 2
Attacks: Bite, bump
SA: Nauseating spit
SQ: None
Int: Mindless
Environment: Cavern/Underground
Organization: 2-20
Sources: B4, D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia
Notes: stone gray, giant grasshoppers
Masher
Size: C
HD: 20
Attacks: Bite, sting
SA: LVT
SQ: None
Int: Mindless
Environment: Sea
Organization: Solitary
Sources: AC9, DMR2
Notes: immense segmented sea worm
Mason Wasp, Giant
Size: M
HD: 6+1
Attacks: Bite and sting
SA: Fire breath, fiery bite, poison sting, dying curse
SQ: Immune to fire
Int: Low (5-7)
Environment: Tropical/Plains or desert
Organization: 1-2
Sources: MC13
Notes: Can be used as mounts or pets.
Mortiss
Size: Varies
HD: 1-100
Attacks: Numerous bites
SA: Delusion-inducing sting, hull damage, web
SQ: Withdraw into tube
Int: Mindless
Environment: Space/Non-moon, non-planet
Organization: Colony
Sources: MC7
Notes: Will probably need to be adapted beyond space.
Animal, Mulworm
Size: F
HD: 1 point
Attacks: None
SA: LVT on contact (also sprays out of skin when injured)
SQ: None
Int: Mindless
Environment: Verdant Belt
Organization: 1000-10,000
Sources: Dark Sun MC2
Notes: off-white caterpillar that lives only to become a butterfly
Nay-Churr
Size: C
HD: 15 to 25
Attacks: Swallow
SA: Swallow
SQ: Convulsion
Int: Mindless
Environment: Space
Organization: Solitary
Sources: MC7 (SJ)
Notes: The swallow ability is more similar to the leviathan's gulp ability: it simply opens its mouth and scoops stuff up.
Nipper
Size: F
HD: 1 hp
Attacks: Bite
SA: Con drain, due to creatures multiplying within body
SQ: None
Int: Mindless
Environment: Astral Plane
Organization: 3-60
Sources: D&D Immortals set
Notes: minute centipede pests
Opilionid (Cave Harvestman)
Size: L
HD: 3+3
Attacks: Bite
SA: Leap attack, jet of acid
SQ: Darkvision, scent, immune to paralysis
Int: Mindless
Environment: Ruins or underground
Organization: 1-20
Sources: Dragon #118
Notes: Fond of carrion crawler flesh.
Giant Oyster
Size: ?
HD: 10
Attacks: “Bite”
SA: None
SQ: None
Int: Mindless?
Environment: Shallow water
Organization: ?
Sources: X1
Notes: appears within the module text
Parasite, Bloodring
Size: T
HD: 1/2
Attacks: -
SA: Blood drain
SQ: Disguise, 30% spell resistance, vulnerable to cure disease
Int: Mindless
Environment: Any land
Organization: 1
Sources: City of Delights, MCA1
Notes: Looks like a ring.
Parasite, Wizard Lice
Size: T
HD: 1 per nest
Attacks: -
SA: Spell draining (lose 1 random spell/day)
SQ: 10% spell resistance, vulnerable to cure disease, weapon immunity
Int: Mindless
Environment: Urban
Organization: 1 nest
Sources: City of Delights, MCA1
Notes: Looks like a ring.
Parasite, Vilirij
Size: T
HD: 1+1
Attacks: Bite
SA: Blood drain, anasthetic bite
SQ: Disguise, vulnerable to cure disease
Int: Semi (2-4)
Environment: urban
Organization: 1
Sources: City of Delights, MCA1
Notes: Looks like a patch of discolored skin.
Pasari-niml ("Mants")(Warrior/Noble/Calipha)
Size: T/T/T-S
HD: 1/2/3-6
Attacks: 2 legs or weapons (darts and knives)[warriors and nobles]; bite
(calipha)
SA: Fear aura, swarmfighting, create pitfall
SQ: Burrowing
Int: Avg (8-10)/Very (11-12)/Very (11-12)
Environment: Any land
Organization: 3d4/1d2/1
Sources: City of Delights, MCA1
Notes: These seem more like magical beasts or aberrations.
Pakubrazi
Size: L
HD: 6
Attacks: Claw/Claw/Bite
SA: Blood drain, taint causes victims to partially transform into insects
SQ: Polymorph into humanoid forms
Int: Average (8-10)
Environment: Urban and inhabited areas
Organization: 1-4
Sources: Dark Sun MC2
Notes: CE alignment, resembles giant tick/fly cross
Pernicon
Size: F
HD: 1-4 hp
Attacks: Bite
SA: Con damage
SQ: None
Int: Semi (2-4)
Environment: Desert
Organization: 4-40 (or as swarm)
Sources: FF, MC14
Notes: Would probably be best as a swarm
Piranha Ant
Size: Swarm
HD: 1 hp/10 ants
Attacks: Swarm (damage 1d4 x victim's AC)
SA: Surprise
SQ: None
Int: 8 (hive mind)
Environment: Temperate urban
Organization: Colony
Sources: Dragon Ann #3
Notes: Another precursor to the swarm subtype, statting up individuals but describing how they function as a swarm
Polyroach (Standard/Large/Huge/Giant)
Size: Tiny/Tiny/Small/Medium
HD: 1 hp/2 HD/4 HD/6 HD
Attacks: None/bite/bite/bite
SA: Disease ("similar to rats")
SQ: Merge, Scatter (smaller roaches can merge to form bigger ones; larger ones can scatter into smaller swarms)
Int: Mindless
Environment: Any non-arctic
Organization: Colony (1-200/1-20/1-4/1)
Sources: Dragon Ann #3
Notes:
Pulp Bee
Size: S
HD: 7
Attacks: Sting
SA: Paralysis/poison
SQ: None
Int: Mindless
Environment: Scrub plains
Organization: Hive (1-4)
Sources: MC12
Notes: Produce pulp that hardens into woodlike consistency, which is prized by humanoids.
Ring-Worm
Size: F
HD: 1 hp
Attacks: ---
SA: Feeds parasitically on wearer's magical energy, bond with skin
SQ: None
Int: Mindless
Environment: Any
Organization: Solitary
Sources: MC11
Notes: Looks like a plain gold ring that detects as a magic item
Robber Fly
Size: S
HD: 2
Attacks: Bite
SA: None
SQ: None
Int: Mindless
Environment: Open, Ruins, Woods
Organization: 1-6
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia
Notes: carnivorous, hide in shadows and surprise
Rot Grub: even though we just sent it in for the last query, we could always try it again…
Carnivorous Scallop
Size: M
HD: 4+4
Attacks: Ram
SA: Entrapment, camouflage, poison cloud
SQ: -
Int: Animal (1)
Environment: Tropical shallows
Organization: 1-4
Sources: Dragon #116, MCA4
Notes:
Scorpion, Barbed
Size: L
HD: 9
Attacks: Claw/Claw/Sting
SA: LVT, improved grab
SQ: Barbs damage melee opponents
Int: Mindless
Environment: Any land
Organization: 1-4
Sources: Dark Sun MC2
Notes:
Scorpion, Gold
Size: T
HD: 2
Attacks: Claw/Claw/Sting
SA: LVT
SQ: None
Int: Mindless
Environment: Any land
Organization: 1-4
Sources: Dark Sun MC2
Notes: Golden-carapaced scorpions
Scrab
Size: S (nest mother L)
HD: 5 (leader 7; nest mother 13)
Attacks: 2 pincers or 2 weapons
SA: Possible spell use, psionics
SQ: None
Int: High (13-14)
Environment: Sandy wastes, stony barrens
Organization: Nest (2-12)
Sources: MC12
Notes: Not really vermin...more like aberrations.
Scum Creeper
Size: D
HD: 1
Attacks: Bite
SA: Attach, blinding
SQ: None
Int: Mindless
Environment: Underground
Organization: 2-24
Sources: MM2
Notes: Slug-like, climb walls
Sea Snail
Size: H
HD: 12
Attacks: Bite
SA: Paralytic poison, wail charms/summons tritons
SQ: None
Int: Mindless
Environment: Large bodies of saltwater
Organization: 1
Sources: MC5
Notes:
Sea Worm (Echyan)
Size: L
HD: 5
Attacks: Bite
SA: Blood drain, swallow whole
SQ: Aversion to daylight
Int: Mindless
Environment: Tropical seas, coasts, and rivers
Organization: School (7-12)
Sources: Red Steel online MC, MCA4
Notes:
Serplar
Size: L
HD: 4
Attacks: Touch
SA: Acid touch, improved grab, envelop
SQ: Scent, tremorsense, immunity to cold and acid, amorphous, vulnerability to fire
Int: Mindless
Environment: Land, underground, warm aquatic
Organization: 1-4
Sources: Dragon 139
Notes: large, spongy worm-like creature
Sink Worm
Size: G or C
HD: 14
Attacks: bite
SA: swallow whole
SQ: Phasing, stealth, tremorsense
Int: Mindless
Environment: Sea of Silt, sandy wastes
Organization: Solitary
Sources: MC12
Notes:
Skrit
Size: L
HD: 6
Attacks: Claw/Claw/Bite
SA: Paralysis, dissolve creature
SQ: Camouflage
Int: Mindless
Environment: Desert
Organization: Solitary
Sources: MC4
Notes: Domed carapace beetle-creatures
Giant Slug
Size: H
HD: 12
Attacks: Bite
SA: Spit acid
SQ: Immunity to blunt weapons
Int: Mindless
Environment: Underground and wetlands
Organization: Solitary
Sources: MM, MC2, MonMan
Notes:
Spider, Asteroid
Size: M
HD: 5+2
Attacks: 6 legs or 1 bite
SA: Improved grab, paralysis, web
SQ: Store air in webbing
Int: Mindless
Environment: Asteroids
Organization: Colony (1-8)
Sources: MC7
Notes: Will probably need to be adapted beyond space.
Barrel Spider
Size: L
HD: 4+4
Attacks: Bite
SA: Blindsense, sunder armor, stunning/deafening hiss
SQ: -
Int: Mindless
Environment: ?
Organization: 1-8
Sources: Dragon #67
Notes:
Giant Spider (Black Widow)
Size: M
HD: 3
Attacks: Bite
SA: LVT
SQ: None
Int: Mindless
Environment: Ruins, Woods
Organization: 1-3
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia
Notes: web-spinner
Giant Bolas Spider
Size: L
HD: 5+5
Attacks: Bite
SA: Silk bolas
SQ: Detect magic
Int: Low
Environment: treetops
Organization: 1 or 2-5
Sources: Dragon #118
Notes:
Boleadore Spider
Size: L
HD: 4+4
Attacks: Bite
SA: Bola web
SQ: -
Int: Mindless
Environment: ?
Organization: 1-4
Sources: Dragon #67
Notes:
Spider, Brain
Size: M
HD: 8
Attacks: Bite and 4 jagged forelimbs or with grafted weapons
SA: Poison, graft weapons, psionics
SQ: Disguise, vulnerable to cure disease
Int: Semi (2-4)
Environment: Subtropical caverns
Organization: 1d6
Sources: Dragon Mountain, MCA1
Notes: Pack hunters that feed on "cerebral nectar".
Spider, Crystal
Size: L
HD: 4
Attacks: 2 forelegs and bite
SA: poison, grab, light beams
SQ: inertial barrier, glass webs, susceptible to shatter spell
Int: Semi (2-3)
Environment: Any
Organization: Solitary
Sources: MC12
Notes:
Crab Spider
Size: M
HD: 2+2
Attacks: Bite
SA: -
SQ: Chameleon
Int: Mindless
Environment: ?
Organization: 1-6
Sources: Dragon #67
Notes:
Giant Spider (Crab Spider)
Size: M
HD: 2
Attacks: Bite
SA: LVT
SQ: None
Int: Mindless
Environment: Cavern, Ruins
Organization: 1-4
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia
Notes:
Daddy Longlegs
Size: M
HD: 2+2
Attacks: Bite
SA: Gas cloud
SQ: Avoid non-reach weapons, spinning concealment
Int: Mindless
Environment: ?
Organization: 2-15/15-25
Sources: Dragon #67
Notes:
Spider, Dark
Size: M
HD: 6
Attacks: Claw/Claw/Bite
SA: Psionics, LVT, webs
SQ: None
Int: High to Exceptional (13-16)
Environment: Underground
Organization: Tribe (2-20)
Sources: Dark Sun MC2
Notes: probably Aberration
Goblin Spider
Size: L
HD: 6-9
Attacks: claw/claw
SA: Surprise, improved grab
SQ: DR, SR, tremorsense
Int: Low (5-7)
Environment: Temperate and warm mountains and forest
Organization: Solitary or family (1-4)
Sources: MC6
Notes: NE in alignment, trap-door spider
Giant Hunting Spider
Size: M
HD: 2
Attacks: Bite
SA: None
SQ: None
Int: Mindless
Environment: ?
Organization: 1-4
Sources: M2, AC9, DMR2
Notes: watchdogs for primitive societies
Jumping Spider
Size: M
HD: 2+2
Attacks: Bite
SA: Mighty leap
SQ: Camouflage
Int: Mindless
Environment: ?
Organization: 1-12
Sources: Dragon #67
Notes:
Giant Marine Spider
Size: H
HD: 7
Attacks: Bite
SA: LVT
SQ: None
Int: Semi (2-4)
Environment: Salt water
Organization: Solitary or pair
Sources: MM2, MC1, Mon Man
Notes:
Spider, Mountain
Size: M
HD: 5
Attacks: Bite
SA: Paralysis venom, (10% have psionics)
SQ: None
Int: Exceptional (15-16)
Environment: Any
Organization: Pack (5-20)
Sources: Dark Sun MC2
Notes: very intelligent, and use tricks to catch prey
Net-throwing/Fishing Spider
Size: L
HD: 4+4
Attacks: Bite
SA: Throw web/draglines
SQ: -
Int: Mindless
Environment: ?
Organization: 1-10
Sources: Dragon #67
Notes:
Polar Spider
Size: L
HD: 6+6
Attacks: Bite
SA: Poison
SQ: Camouflaged in snow, immune to cold
Int: Low
Environment: arctic regions
Organization: 1 or 2-5
Sources: Dragon #118
Notes:
Raft/Swamp Spider
Size: M
HD: 2+2
Attacks: Bite
SA: Water walk
SQ: Hold breath
Int: Mindless
Environment: ?
Organization: 1-6
Sources: Dragon #67
Notes:
Giant Sand Spider
Size: M
HD: 2
Attacks: Bite
SA: LVT
SQ: None
Int: Mindless
Environment: Desert or barrens
Organization: 1-4
Sources: AC9, DMR2
Notes: burrow under the surface and burst out to surprise prey
Giant Shroud Spider
Size: M
HD: 5
Attacks: Bite
SA: Webs, paralysis
SQ: DR/silver or magic
Int: 4
Environment: ?
Organization: 1-2
Sources: AC9, DMR2
Notes:
Spider, Silt
Size: D
HD: 1
Attacks: Bite
SA: Paralysis venom
SQ: None
Int: Mindless
Environment: Silt
Organization: 6-36
Sources: Dark Sun MC2
Notes:
Spitting Spider
Size: M
HD: 2+2
Attacks: Bite
SA: Spit silk
SQ: -
Int: Mindless
Environment: ?
Organization: 1-4
Sources: Dragon #67
Notes:
Giant Spider (Tarantella)
Size: M
HD: 4
Attacks: Bite
SA: Spasming poison that causes other creatures to dance as well
SQ: None
Int: Mindless
Environment: Ruins, Woods
Organization: 1-3
Sources: D&D Basic Rules (1981), D&D Basic Set (1983), Rules Cyclopedia
Notes: web-spinner
Trap-door/Purse Spider
Size: M
HD: 2+2
Attacks: Bite
SA: Web snares
SQ: Trap door
Int: Mindless
Environment: ?
Organization: 1-12
Sources: Dragon #67
Notes:
Giant Trap Door Spider
Size: L
HD: 4
Attacks: Bite
SA: LVT, webs, drag into tunnel, surprise attack
SQ: Tremorsense
Int: Mindless
Environment: Warm and temperate plains, forest
Organization: Family
Sources: MC4
Notes:
Giant Water Spider
Size: L
HD: 3
Attacks: Bite
SA: LVT
SQ: None
Int: Semi (2-4)
Environment: Fresh water
Organization: Solitary or pair
Sources: MM, MC1, Mon Man
Notes:
Whip Spider
Size: M
HD: 2+2
Attacks: 2 whips and bite
SA: -
SQ: -
Int: Mindless
Environment: ?
Organization: 1-4
Sources: Dragon #67
Notes: This may be in City of the Spider Queen
Whisper Spider
Size: H
HD: 8
Attacks: Bite
SA: LVT, webs, blinding webs
SQ: Jump, stealth
Int: Low (5-7)
Environment: Warm and temperate plains, forest, hills, mountains
Organization: Family
Sources: MC4
Notes: Can form its webs into any shape to fool other creatures
Wolf Spider
Size: M
HD: 2+2
Attacks: Bite
SA: -
SQ: Scent, sprint, carries babies
Int: Mindless
Environment: ?
Organization: 1-12
Sources: Dragon #67
Notes:
Huge Wood Spider
Size: S
HD: 1
Attacks: Bite
SA: LVT
SQ: None
Int: 2
Environment: Forest
Organization: 1-4
Sources: AC9, DMR2
Notes:
Spider-kin, Planar Spider
Size: M
HD: 5-12
Attacks: Bite
SA: Poison
SQ: Phasing
Int: Very (11-12)
Environment: Any
Organization: Solitary
Sources: D&D Master Set, Mystara MC
Notes: Some are spellcasters. May be related to phase spiders. Probably magical beasts.
Spider-kin, Plopped
Size: T
HD: 1/2
Attacks: Bite
SA: Poison, leap
SQ: Thief abilities (hide/move silently/climb)
Int: Mindless
Environment: Mountains
Organization: Solitary
Sources: Mystara MC
Notes:
Spirit Centipedes appear in 3E OA, and goblin spider is mentioned there as well, as a fiendish monstrous spider with alternate abilities.
Starfish, Giant (Giant Sunstar)
Size: G
HD: 10 (or 12)
Attacks: 1-10 (or 1-12) arms
SA: Ship damage
SQ: Half damage from blunt weapons, slow regeneration
Int: Semi (3-4)
Environment: Any saltwater
Organization: 1-2
Sources: RA2 Ship of Horror, MCA4
Notes:
Steam Weevil
Size: T?
HD: 1/2
Attacks: Bite
SA: Burn
SQ: immunity/resistance to fire
Int: Mindless
Environment: Underground
Organization: 4-24
Sources: B5, AC9, DMR2
Notes: thrive on heat and pressure
Stegocentipede
Size: H
HD: 9
Attacks: Bite and tail
SA: LVT
SQ: Spine armor
Int: Mindless
Environment: Any
Organization: Solitary
Sources: MM2
Notes:
Stone Termite (King/Queen/Soldier/Worker)
Size: Tiny (all)
HD: 1-1 HD/1-4 hp/ 1 hp
Attacks: Swarm (damage 1d4 x victim's AC)
SA: Acid spray (soldier only; 10 ft. range, 1d2 dmg)
SQ: Eat stone, deal structural damage
Int: Mindless
Environment: Temperate urban or subterranean
Organization: Colony (1/1/2-16/10-100)
Sources: Dragon Ann #3
Notes:
Syllix = Doesn't appear to fit the "vermin" criteria...more of an aberration.
Throat Leech: probably best as a hazard
Sources: FF, MC2
Giant Tick
Size: S
HD: 2-4
Attacks: Bite
SA: Blood drain
SQ: None
Int: Mindless
Environment: Forest, underground
Organization: 3-12
Sources: MM
Notes:
Tiger Fly (Male/Female/Larva)
Size: M
HD: 6/4/1
Attacks: 2 claws or sting (male) sting (female)
SA: LVT (male), paralysis, implant eggs (female)
SQ: None
Int: Mindless
Environment: ?
Organization: 3-18
Sources: FF
Notes:
Trosip
Size: T
HD: 1 hp
Attacks: -
SA: Suffocation
SQ: Tremorsense/blindsense, camouflage, high bonus to Move Silently
Int: Mindless
Environment: Any interior or subterranean
Organization: Colony (4d6)
Sources: Savage Coast
Notes: Living dust bunnies that attack only sleeping creatures.
Tunnel Worm
Size: H
HD: 9
Attacks: Bite
SA: Lunge at +2 to hit, Improved Grab, Rend Armor
SQ: None
Int: Mindless
Environment: Underground
Organization: 1-6
Sources: MM2, MC2, MonMan
Notes: Giant centipede
Urchin (Black/Green/Red/Silver/Yellow)
Size: S
HD: 1/2/3/5/4
Attacks: Spine (ranged) per round: 2/2/3/5/4
SA: Clairvoyance (+2 to attack rolls), LVT
SQ: None
Int: Semi (2-4)
Environment: Sea bed, coast
Organization: 1-6/1-4/1-4/1-2/1-3
Sources: FF, MC2, Mon Man
Notes:
Urchin, Land
Size: S
HD: 3
Attacks: Spine (ranged) 6 per round
SA: Clairvoyance (+2 to attack rolls), LVT
SQ: Smoke cloud
Int: Mindless
Environment: Temperate and warm land
Organization: Solitary or pair
Sources: MM2, MC2, Mon Man
Notes:
Wall-Walker
Size: M
HD: 6
Attacks: 2 claws and bite or stinger
SA: Paralysis, springing sting attack
SQ: Psionics, immunity to fire
Int: Low (5-7)
Environment: Subterranean
Organization: 1-2 (4-16)
Sources: City by the Silt Sea, MCA2
Notes: Combine the features of spiders and reptiles.
Water Termite (swamp/fresh water/salt water)
Size: T-M
HD: 1/2/4
Attacks: Bite?
SA: Inky spray paralyzes
SQ: None
Int: Mindless
Environment: Swamp, Lake, Ocean
Organization: 1-4/1-3/2-7
Sources: Rules Cyclopedia
Notes: eat wooden ship hulls
Webbird
Size: D
HD: 1/2
Attacks: Bite
SA: Webs, egg insertion
SQ: Psionics, immunity to fire
Int: Semi (2-4)
Environment: Temperate forest
Organization: Flock (12-48)
Sources: MM2, MCA2
Notes: Looks like a bird, really an insect or arachnid; Often lair with stirges.
Whiz-Bang Beetles
Size: F
HD: 1 hp
Attacks: -
SA: Explodes when hitting fire
SQ: Can sense fire
Int: Very low
Environment: Underground
Organization: 5-50
Sources: Dragon #29
Notes: Could be a swarm; honey has magical effects.
Worm, Lukhorn
Size: H
HD: 10
Attacks: Bite
SA: Digestive acid, sonic screech, swallow whole
SQ: Camouflage, malleable body
Int: Semi (2-4)
Environment: Underdark
Organization: Solitary
Sources: Dragon Annual #1, MCA4
Notes:
Red Worm
Size: L
HD: 2+2
Attacks: Bite
SA: Poison
SQ: Tremorsense
Int: Mindless
Environment: Subterranean
Organization: Brood (2-12)
Sources: AC9, DMR2, Mystara MC
Notes:
Slime Worm
Size: G
HD: 2+2
Attacks: Bite
SA: Swallow whole
SQ: Camouflage, sticky slime
Int: Mindless
Environment: Subterranean
Organization: Solitary
Sources: X2, AC9, DMR2, Mystara MC
Notes:
Xerichou
Size: S
HD: 3
Attacks: 2 razor-wing slashes
SA: Psionics
SQ: None
Int: Average (8-10)
Environment: Any dry land
Organization: Solitary or flock (6-36)
Sources: Dark Sun MC2
Notes: flying, armored, worm-like predators, possibly better as Aberration
Zurchin
Size: T
HD: 1+1
Attacks: 2 spines
SA: Poison, shoot spines, implant eggs
SQ: -
Int: Mindless
Environment: Wildspace, asteroid fields
Organization: 1-3
Sources: MC9
Notes: Will probably need to be adapted beyond space. Have some ties to neogi.