Stonefish

Among reef rubble, a stonefish has the color, texture and patience of the stones around it. It does not pursue prey larger than its mouth. The danger is weight: a boot, bare foot or grasping hand drives venomous spines upward, turning an ordinary step through shallow water into a race for treatment.

Venom Spine: poison, melee 5 ft, +2 to hit, 1 damage. A creature that steps on, grabs or pins the stonefish makes a Tough save; on a failed save, it takes 2d8 poison damage and becomes Weary for 1d6 hours.

Living Stone: noticing the fish among natural rock requires a successful Chance Roll. A pole, net or thick-soled boot can move or cross its space safely once it has been found. The stonefish never pursues a retreating creature.