A wave of swift-moving spines rushes forward—a roiling tide of dangerously fast sea urchins.
The venom of ravenous urchin swarms stiffens muscles and locks joints into painful configurations. The save DC is Constitution-based.
Each time a creature moves through a space occupied by a ravenous urchin swarm or starts its movement in such a space, it runs the risk of a ravenous urchin moving underfoot. The creature must succeed at a DC 13 Reflex save or take 1 point of damage plus poison. Additionally, the affected creature's movement speed is reduced by half because its foot is wounded. This movement penalty lasts for 24 hours, until the creature is successfully treated with a DC 15 Heal check, or until it receives at least 1 point of magical healing. A charging or running creature must immediately stop if it steps on a ravenous urchin. Any creature moving at half its speed or slower can pick its way through a tidal pool of ravenous urchins (but not a ravenous urchin swarm) with no trouble. The save DC is Constitution-based.