Gremishka

Across a dim cellar a gremishka might be taken for a big cat or a little dog: furred in any color, with pointed ears, a jutting muzzle, and a mouth and slit-pupiled yellow eyes too large for its face. It has no wings. Its clever fingers can work any tool, though it drops or hides a weapon within the hour, and it skips armor and clothes while understanding both. Each speaks gremlin and its own tongue, and many know six or more human languages.

Gremishka fight only when cornered. Their speed explains their fine Armor Class and grants +4 on saves against area effects, and they get +2 to hit anything over 4 feet tall. Their method is the swarm: each one needs a single hit to latch on, then bites for 1d3 per round automatically, while half the pack cuts straps, opens clasps and grabs loose gear. Allies swinging at the heap endanger the victim, who takes any damage beyond what kills the targeted gremishka. A strong show of force often breaks their weak morale, and they flee with their loot.

They den in basements and under large houses, ideally with easy access to many rooms; sunlight annoys but does not hurt them. Their hoard is a random heap of stolen trinkets, a few of real worth. They live to enrage bigger creatures, setting vicious, destructive and often elaborate pranks while spying from walls and floorboards. No gremishka leads, but whoever proposes a prank directs it, and victims usually hear shrill chittering laughter when it goes off.

They eat anything and snare rats, cats and dogs. Some briefly bond with local children their own size. Kobolds, dogs, giant spiders, large snakes and above all humans hunt them.