"M" is for "Malignid"

Malignid

No. Enc.:  2d4 (3d6)
Alignment:  Chaotic
Movement:  165' (55')
Armor Class:  4
Hit Dice:  5
Attacks:  4 (2 claws, 2 bites)
Damage:  1d4+1 / 1d4+1 / 1d6 / 1d6, + Poison
Save:  L5
Morale:  10
Hoard Class:  VIII (x3), 3 Foodstuffs / Junk
XP:  500

Malignids are screeching, scurrying, aggressive insects that nest in tainted areas such as glowing waste dumps and seeping landfills.  They reach 4'-5' high at the shoulders of their powerful, ape-like forelimbs, and their bizarrely-jointed back legs provide great speed and leaping ability.  The angrier the malignid, the more its tympanic membranes throb and flutter.

Malignids are ferocious combatants, with rending claws and dual sets of razored mandibles. And everything about them is toxic, as their nails inject a Class 10 paralytic agent, and their bites a Class 4 venom.

For reasons unknown, malignids hoard refuse, trinkets, and broken artifacts.  And some claim that they've seen the creatures using tools....

Mutations:  Toxic Weapon (Venom) (x2)