Dungeon Dwellers - the little guys

In your typical dungeon you remember stuff like the rust monster and carrion crawler shared lair, or the red feathered owlbears that were fire proof but everyone forgets the little things beneath foot that squirm and crawl but dont usually get noticed.

Why look you may well ask. Dungeon rangers know some of these are attracted to certain creature lairs and some creatures feed and encourage select dungeon crawlies. Besides food some have practical uses or even are good for dungeon craft materials like glue. Some are alternative material components for spells. others are an occasional risk or are used in traps. I fully support dungeon druidry. This table might be fun for 1st lv or zero level characters or for a solo romp or a trip to the junior dungeon you let teens into alone.

amended a few things Mike Patton suggested on old school gamers - leeches and add tentacles
amended again with ants (thanks S. D. houston), micro-undead, more baby monsters

1d100 Dungeon critter table

01 Dungeon trapdoor spider - blends into stonework bottom few feet of wall or in doorways - poison+2 save
02  Dungeon redback spider - black orb with scarlet eye mark on back builds scraggly webs under benches, furniture, goods left against walls, holes - poison aggressive with nest
03-04  Dungeon rat eating spider - a 2 hand size spider with necrotic bite 1 dam + 1d6+2 venom damage save vs poison for half - not hostile but might be startled and defend self
05-06  Dungeon camel spider - foot long creatures look part lobster. Paralyze you with venom then eat 1hp per 1d10 minutes, others may join in meal, attack sleepers unless desperate
07-08  Dungeon scorpion - up to foot long 1d4 hp, Poison+2 save, aggressive 1d4 per group
09-11  Dungeon centipede - up to foot long 1d4 hp, Poison+2 save, angry if disturbed nest or while eating
12-14 Dungeon king rats - 1-3 foot long 1d4 HP, 1d4 bite, diseased, good food and hide 3d4
15 Dungeon rat mutant - bizarre specimen with wings, scorpion tail, bald, green, intelligent
16-17 Dungeon Giant rat - 1-3 HD (1 yard per HD) 1HD 1d6 bite, 2HD 2d3 bite, 3HD 2d6bite
18-19 Dungeon rat swarm - 1d20+6 1hp rats in a swarm more aggressive than regular rats 1dam to victim/round, 1 victim every 6 rats
20 Ball of rats - ball of 3d6+4 entangled rats
21 Dungeon Hens 1d6 and Rooster 1d4 HP and damage - wild, feral or somebodies livestock
22 Dungeon rabbits - 1d3 HP 1d4 attack if cornered, uses dungeon as thoroughfare, possible feral food beast
23 Dungeon hedgehog - 1-3 foot long eating bugs, grubs and other critters, good eating, harmless
24-25 Dungeon Cat - usually flee but may be curious and follow
26 Dungeon bobcat 1HD cat can attack for 1d6, normally cautious but curious
27-30 Dungeon Dog - usually medium dogs, stray pet, watch dogs on patrol 1d6 or feral dog pack 2d6 - territorial, will have allies it an howl for
31-32 Dungeon Swine and subterranean 2HD Boar with infravision who eat dungeon rubbish
33 Dungeon hog lost from herd eating some lovely muck
34-35 Dungeon Lizard - scavenging monitor lizard 1HD, attracted by smells of blood or rations
36 Dungeon gecko - hides above doors, chamo blends in, may hide near door frames, 1d4 bite, squeak loudly then flee if startled, eats bugs, is tasty
39 Discover you are crawling with leeches - 1hp damage
38-40 Dungeon frog or toad - looking for bugs, puffs up if sees bigger things and moves away, 2HD 1d6 bite, tasty legs if frog pr good leather if toad
41-42 Dungeon froglings or toadlings - 1d6 large 1-2 hand size frogs or toads looking for grubs
43 Tentacle from drain or water grabs your foot will give up if hurt or cant drag into hole
44 Badger hunting or using as thoroughfare 1-2HD
45 Dungeon turtle - slowly wandering turtle looking for bugs, might stay near water or drainpipe, tasty, looks tired and resigned to fate, linkboys eat them
46-48 Dungeon dung beetle - collects dung and rolls away and stores in nest neatly
49-50 Dungeon giant flies 1d4 HP 1d4 damage, 1d6 in group, aggressive hit and run
51-53 Dungeon maggots - good bait and good eating for some, 1HP and bite for 1 HP, 1d10 maggots probably on some corpse or some dung
54 Dungeon wasp - 1d6 large 1d4 HP wasps with 1d4 stings
55 Dungeon weasel
56-57 Ferrets - a lost pet or hunters gone feral in a family of 1d6, harmless unless your a bug
58-60 Dungeon Earth Worms - up to a foot long come from its hole to eat some rubbish, good bait
61-63 Dungeon giant worm - up to a 1 yard worm with a 1d4 HP and bite
64 Baby jelly or ooze or cube eating some dungeon rubbish
65-68 Dungeon grubs - 2d20 grubs attack for 1hp then live inside host as a parasite - when worms exeed HP victim bursts, 1d6 attack a person each round
69 Dungeon fleas - infested area spreads to party, lose 1 hp per day till treated, with weekly disease check
70-73 Dungeon thread worms - 2d6 sticky threads attack and cling to victim from wet patch on ground or near food or rubbish for 1hp per worm then live inside host as a parasite - when worms exeed HP victim bursts open
74-75 Dungeon mosquitoes - swarm inflict 1hp per round for 1d4 rounds then leave
76 Dungeon giant mosquito - 1d4 HP, 1d3 bite then suck 1d3 per round till dear, diseased
77 Giant tick 2HD, 1d6 bite then suck 1d4/rnd, diseased
78 Small piercer or several 1d4 or 1d6 dam
79-80 Jackal or fox looking for scraps, possibly see parents with some young 1d6, will flee
81 Baby purple worm 1d4 HP 1d4 bite or stinger - kill and eat now or else
82-85 Small cave cricket 1d4 HP and 1d3 bite, 1d6 may congregate near scraps
86-87 1d100 cockroaches - may get into party stuff and lay eggs
88 Baby mimic 1d4 HP grabs then 1d4 per round crush, disguise as doorknob, gem, dagger
89 Undead hand or other body part or undead small creature like a rat zombie
90 Baby carrion crawler 1d4 HP one sting save vs paralysis +4, leave nest in groups of 1d6
91 Baby trapper covers single floor stone usually near doorway sometimes in group of 1d6 - 2d4 HP grab then crush for 1d4 per round, surprise
92 Baby cave fisher - sits above doorways, try to eat party pets or hobbits, 2HD, entangling fisher line 2x1d6 lobster claws when victim close
93 Ants, inch ants, termites, footlong builder or mining ants, a single grumpy dog sized ant
94 Cave lobster (Dungeon Yabbie) 1d4, usually hide near drains or water on in puddle, nip for 1d4 if surprised then flee to water
95 Dungeon Adder - 1d4 HP 1hp bite + Poison+2 save
96 Dungeon constrictor 2HD - 1d6 crush and 1d4 bite - small adventurer or pet is tempting
97 Gremlins or faeries play cruel pranks, pick pockets, hotfoot, steal food, cut rope, hole battles, etc
98 Lost familiar creature may be shy or just follow or be friendly
99 Rat or weasel or cat looking but actually a quasit or imp or brownie or other small curious shape shifter
00 Spherical one eyed furry ball follows party, makes cute noises and eats party victims, it is a baby beholder, if scared it has a single flash strobe Save vs blindness for 2d4 rounds -1 to hit for 1 hour after, it usually flees and goes down a hole, very fast and harmless at this age but most get eaten

1d20 Some stuff that grows

1 Slime mold 10 foot patch of slippery ground needing a Dex check
2 grey mold - covers goods or rubbish everyone in square save vs poison or 1d6 rounds helpless sneezing loudly
3 Dungeon mold - exposure spreads black smut spots on body, if not treated skin turns black or green or other colour till treated
4 Puffballs burst on touch fills with black dust 10ft square
5 Cave pustules - look like rocks but explode white puss like goop on all in squre, ruins cloth, leather, rope if not sterilized and turns to more cave pustules in 24 hrs
6 Screamer shrooms - mushrooms that screams loudly if disturbed for 1 minute
7 Explodestools - 1d6 blast all in 5 ft circle, can set off chain reaction - used like minefilds
8 Glowstools - glowing cave fungi makes poor candles
9 Barn mushrooms - tasty edible fungi, makes great burger or substitute steak
10 Poison toadstool - save vs poison +2, -2 all checks for 6 hrs if save
11 Grandma's Caps - 1d6hp healing shrooms
12 Chaos mushrooms - eater gets a chaos mutation and mild poisoning
13 Magic Mushrooms - bestow potion like effects plus odd side effect
14 Angry Shrooms -  1d4 HP, bite 1d4, pack of 1d6 aggro flesh eaters that hop
15 Dreamers Shrooms - induce sleep and prophetic visions
16 Spirit Shrooms - spirit leaves body and enters spirit world
17 Elf bread - this delicious addictive fungus attunes you to the faerie world for a month
18 Wizard cap - gives you knowledge of a 1st lv spell for 24 hours (only use once per year)
19 Giant Shroom - woody textured with leather like skin grow forever unless stopped
20 Black fungus - sticky glue like residue like tar gets on hands, boots, smells sticks to stuff, vinegar or alcohol to remove