As two actions, the ground in a sphere centered on a point within 20 meters twists and becomes doughlike with hundreds of little teeth. The area becomes difficult terrain for the duration. When a creature moves into or within the area, it takes 2d4 piercing damage for every meter it travels.
At the start of each of your turns if the maws are within 20 meters of you, you can cause them to move up to 2 meters in a direction that you choose. If you spend an action, you can move them up to 10 meters.
You can increase the damage by 1d4 for every two additional mana expended.