I see your twenty scorpions and raise you TWENTY ONE CENTIPEDES. Written with Into the Odd in mind.
1: Black Arrow Centipede (STR 2, DEX 8, WIL 2, 1HP)
About the length of an arrow. Launches itself from cave walls, burying its head into anything it hits for 1d6+1 damage. Must be removed slowly and carefully to avoid another 1d6 damage.
2: Endel's Dasher (STR 2, DEX 10,
WIL 4, 1HP)
A foot long, deep green in colour. Bites for 1d6-1 point of damage. Critical Hit causes the victim loss of 1d6 STR and DEX every round until incapacitated.
3: White Lady Centipede (STR 4, DEX 8,
WIL 4, 2HP)
Chunky, a foot long with a soft white shell. Extremely tasty when cooked.
4: Bristly Boar-Eating Centipede (STR 10, DEX 8, WIL 3, 5HP)
Deep brown, three feet long, able to rear back to reveal a second pair of biting mandibles. Bites for 1d6 Damage and grips on tightly. Picks off young boar in its jungle home.
5: Silver Ghost Finger (STR 4, DEX 8, WIL 5, 2HP)
Able to float slowly through the air by moving its silver hairs in a wavelike motion, which no one can explain.
6: Gnomeshield (STR 6, DEX 5, WIL 2, 3HP, Armour 1)
A flat, two feet long, beetle-like centipede with a dull copper, chitinous back resembling a shield.
7: Manxtail Centipede (STR 4, DEX 6, WIL 2, 2HP)
A foot long, gold and bristly. Anyone fighting it in melee must pass a DEX Save vs 10 or subtract 1 from all attacks as they suffer unbearable itchiness. Water will wash these bristles off.
8: Red Cryer (STR 2, DEX 6, WIL 2, 1HP)
This centipede's bite would do no harm to anything bigger than the insects it feeds on, but when scared it cries out with an ear-splitting noise. Those hearing it nearby must pass a STR Save vs 10 or subtract 2 from any rolls that are not aiming to silence the racket.
9: Drolonid (STR 4, DEX 10, WIL 8, 2HP)
Three feet long, faintly orange and has an unusual fly-like proboscis in place of mandibles, so cannot bite. Will drip corrosive onto anyone passing below for 2d6 damage. Anyone killed will this will be slurped up by the Drolonid when the coast is clear.
10: Juanan Pitpede (STR 13, DEX 8, WIL 3, 13HP)
Bred for competitive fighting, can grow up to five feet in length and extremely bulky.
11: Ulmer's Stinkbug (STR 5, DEX 4, WIL 2, 2HP)
Six inches long. Releases stench when in danger. WIL Save vs 20 to avoid choking loudly and vomiting. Bite is harmless.
12: Gulleater (STR 6, DEX 8, WIL 4, 3HP)
Bite causes 1d6-1 damage. On a Critical Hit poison causes 1d6 DEX loss.
13: Farfan's Cleaner Centipede (STR 2, DEX 4, WIL 2, 1HP)
Six inches long, silver and red in colour. Harmless but will head for metal items and eat any rusted parts, somehow repairing the metal as it moves by.
14: Houndbane Centipede (STR 7, DEX 10, WIL 6, 3HP)
Smooth, black shell and two feet long. On a Critical Hit lose 1d6 WIL.
15: Greater Frilled Longbug (STR 4, DEX 8, WIL 6, 2HP)
An unusually brightly coloured two-foot centipede. On a Critical Hit lose 1d6 STR. Very cowardly when not fighting its own kind.
16: Nostril Centipede (STR 2, DEX 8, WIL 2, 1HP)
A few inches long. Seeks the nostrils of sleeping passers-by and enters without waking (unless the sleeper passes an INT Save vs 25) to lay its eggs. A month later the babies fall out of the nose, causing 1d6 WIL loss.
17: Sandtrap Biter (STR 8, DEX 6, WIL 4, 4HP)
Three feet long. Lies in wait under the sand of beaches to snatch prey. On a Critical Hit the target is pulled down into the centipede's pit, where others may wait.
18: Iplenx (STR 20, DEX 6, WIL 12, 20HP)
Purely mythological. Some ten feet long and taller than a man. Can open its eyes to release a beam of light on a target for 2d6 damage.
19: Carverbug (STR 2, DEX 4, WIL 8, 1HP)
A few inches long, thought to be transformed victims of a sorcerer. They are able to leave a trail of an ink-like substance and have known to communicate intelligently this way, particularly in giving directions underground.
20: Spinerester Centipede (STR 5, DEX 8, WIL 8, 2HP)
One foot long and sickly yellow. Will crawl onto a sleeping victim's back and bite the back of their neck (unless the sleeper passes a DEX Save vs 20). From here they cannot be removed without injecting a long needle-like protrusion into the victim for 3d6 damage, also doing this if they are damaged. While attached they feed off the victim's blood, reducing all Ability Scores by 1 as long as they are attached.
21: Scorpion-eating Centipede (STR 7, DEX 8, WIL 4, 3HP)
Two feet long, red and slightly velvety to the touch. Bites for 1d6 damage or 1d6+2 against Scorpions.