Aura's Magical Caltrops

As a Utilize action, you can spread these magical caltrops from their bag to cover a 5-foot-square areas within 5 feet of yourself. You can retrieve the caltrops as an action by holding the bag in their space.

Once spread, the caltrops hover at random heights in the square, to a maximum of 5 feet high. On entering the space, the creature must succeed on a DC 13 dexterity saving throw or take 1 piercing damage and have its speed reduced to 0 till the start of its next turn as the caltrops stab into its body. If it starts its turn in the caltrop's space, it repeats the saving throw, as the caltrops fly away and attempt to stab it again. On a success, it suffers no effects.