Bloodgrass

A patch of bloodgrass looks like any healthy stretch of green grass, only with somewhat longer blades. Its runners creep in among ordinary grasses of the green fringe lands and forests, and only a close look gives it away.

Anything that treads on the patch is attacked by one or more tendrils that coil around it and suck blood. The target makes a Dexterity check against each attacking tendril to dodge it. A tendril that connects injects a paralytic venom every round, and an ensnared creature must save vs. poison each round until it either tears loose or fails a save, which leaves it paralyzed for 2d6 rounds. The venom accumulates, so saves suffer -1 after two rounds, -2 after four, and worse from there. Breaking loose takes a passed Strength check, and every successful blow lops off one tendril.

Once prey stops moving, extra tendrils close in and burrow, each dealing 1 point a round. Every round, check one tendril for reaching the brain: 5%, plus an extra 1% for each round the victim has been helpless. If it gets there, it laces through the skull and kills in 1d6 rounds.

Tendrils have only 1 hit point each, but speed matters: if the first is not cut away promptly, up to 20 can be striking within 2-5 rounds. A typical clump holds about 20 tendrils in the fringe lands and 30 in the forest, though the largest reach 200.

Drained husks are dropped where they fell, which can tip off a sharp-eyed traveler. Characters with the survival (forest) proficiency get a check to spot the grass, at +4 if they are deliberately searching for it. Druids and rangers notice it with a 5% chance per level.

Nobles and rich merchants of the cities like it as a self-feeding, low-maintenance guard dog for their grounds. A patch has only a 20% chance of holding leftover treasure from some luckless trader or adventurer.

City markets pay up to 5 ceramic pieces for a living specimen, provided the seller brings the mother root along with enough tendrils to keep it alive. Lost tendrils regrow in 7-10 days. Beyond that, it yields nothing useful, and thinking folk treat it as a noxious weed.