Cave Fangs

You create a magical trap in the area that causes deadly stalactites or stalagmites to "bite" an intruder. The magical trap is triggered whenever an enemy creature moves through the affected area. The effect of cave fangs depends on whether you create stalactites or stalagmites (see below). You can place these traps anywhere within close range as free action for the duration of the spell; the trap's radius is 5 feet. Each time you place a trap, the spell's duration is reduced by 10 minutes. Stalactites: Shards of rock drop from above, dealing 3d8 points of bludgeoning and piercing damage (Reflex half). A creature that fails its Reflex save is pinned to the ground under stalactites and rubble, gaining the entangled condition until it can free itself with a successful DC 15 Strength check or DC 20 Mobility check. Stalagmites: Piercing spires of rock erupt up from the ground, dealing 3d8 points of piercing damage and knocking the creature prone (a successful Reflex saving throw halves this damage and avoids being knocked prone). Once the stalagmites appear, they function thereafter as spike stones for 1 minute per caster level and then crumble to dust.